Page 3 : आर सेन्दिल कुमार, , dsUnzh; fo|ky; laxBu], {ks=h; dk;kZy;] ,j.kkdqye, , उपायुक्त, , R. Senthil Kumar, , KENDRIYA VIDYALAYA SANGATHAN, REGIONAL OFFICE,, ERNAKULAM,, KOCHI – 682 020, Ph. No.0484- 2205111(DC), 2203091(Fax)), Website: www.roernakulam.kvs.gov.in, Email :
[email protected], , F.31/Acad/KVS(EKM), , Dated: 01.11.2021, Message, , I feel immense pleasure to publish the study material for class XII Computer Science (083), ., , This support material is prepared incorporating all the recent changes in curriculum and, , assessment process made by CBSE., , I am sure it will definitely be of great help to class XII, , students of all Kendriya Vidyalayas., Getting acquainted with the latest changes will help students to prepare well for the, board examination and enable students to face case based and Multiple-Choice Questions with, confidence. This support material has been prepared by a team of dedicated and veteran, teachers with expertise in their respective subjects., The Support material contains all the important aspects required by the students- the, design of question paper, term wise split up syllabus, summary of all the chapters, important, formulas, Sample question papers, problem solving and Case study questions., I hope that this Support Material will be used by students and teachers as well and will, prove to be a good tool for quick revision., I would like to express my sincere gratitude to the In- charge principal and all the, teachers who have relentlessly worked for the preparation of this study material. Their, enormous contribution in making this project successful is praiseworthy., Meticulous planning blended with hard work, effective time management and sincerity, will help the students to reach the pinnacle of success., , Wish you all the best, ( R Senthil Kumar ), Sh. Jyothimohan N V, Principal, Kendriya Vidyalaya, SAP Peroorkada
Page 4 :
CBSE Term wise Syllabus, Revision of Python topics covered in Class XI, Page No. 1 to 64, , Functions, , Content, , Page No 65 to 92, , Introduction to files, Page No. 93 to 111, , Binary file, Page No.112 to 160, , CSV file, Page No.161 to 178, , CBSE Term – 1 Sample Paper with Solution, KVS Ernakulam Region - Practice Test Question, paper with Marking Scheme
Page 5 :
Computer Science, CLASS-XII, Code No. 083, 2021-22, 1. Prerequisites, Computer Science- Class XI, , 2. Learning Outcomes, Student should be able to, a) apply the concept of function., b) explain and use the concept of file handling., c) use basic data structure: Stacks., d) explain basics of computer networks., e) use Database concepts, SQL along with connectivity between Python and SQL., , 3. Distribution of Marks:, Unit, No., , I, II, III, , Unit Name, , Marks, , Periods, Theory, , Practical, , Computational Thinking and, , 40, , 50, , 25, , Programming - 2, Computer Networks, Database Management, Total, , 10, 20, 70, , 10, 20, 80, , --15, 40, , Unit No, I, II, III, , Unit Name, Computational, Thinking and, Programming - 2, Computer Networks, Database, Management, Total, , Term-1, 35, , Term-2, 5, , ---, , 10, , ---, , 20, , 35, , 35
Page 6 :
4. Unit wise Syllabus, , TERM 1:, Unit I: Computational Thinking and Programming – 2, , , , , , Revision of Python topics covered in Class XI., Functions: types of function (built-in functions, functions defined in module, user defined, functions), creating user defined function, arguments and parameters, default parameters,, positional parameters, function returning value(s), flow of execution, scope of a variable (global, scope, local scope), Introduction to files, types of files (Text file, Binary file, CSV file), relative and absolute paths, , , , Text file: opening a text file, text file open modes (r, r+, w, w+, a, a+), closing a text file, opening a, file using with clause, writing/appending data to a text file using write() and writelines(), reading, from a text file using read(), readline() and readlines(), seek and tell methods, manipulation of data, in a text file, , , , Binary file: basic operations on a binary file: open using file open modes (rb, rb+, wb, wb+, ab, ab+),, close a binary file, import pickle module, dump() and load() method, read, write/create, search,, append and update operations in a binary file, CSV file: import csv module, open / close csv file, write into a csv file using csv.writerow() and read, from a csv file using csv.reader( ), , , , TERM 2:, Unit I: Computational Thinking and Programming – 2, , , Data Structure: Stack, operations on stack (push & pop), implementation of stack using list., , Unit II: Computer Networks, ●, ●, , ●, , ●, ●, ●, ●, , Evolution of networking: introduction to computer networks, evolution of networking (ARPANET,, NSFNET, INTERNET), Data communication terminologies: concept of communication, components of data, communication (sender, receiver, message, communication media, protocols), measuring capacity, of communication media (bandwidth, data transfer rate), IP address, switching techniques (Circuit, switching, Packet switching), Transmission media: Wired communication media (Twisted pair cable, Co-axial cable, Fiber-optic, cable), Wireless media (Radio waves, Micro waves, Infrared waves, Network devices (Modem, Ethernet card, RJ45, Repeater, Hub, Switch, Router, Gateway, WIFI card), Network topologies and Network types: types of networks (PAN, LAN, MAN, WAN), networking, topologies (Bus, Star, Tree), Network protocol: HTTP, FTP, PPP, SMTP, TCP/IP, POP3, HTTPS, TELNET, VoIP, Introduction to web services: WWW, Hyper Text Markup Language (HTML), Extensible Markup, Language (XML), domain names, URL, website, web browser, web servers, web hosting
Page 7 :
Unit III: Database Management, Database concepts: introduction to database concepts and its need, Relational data model: relation, attribute, tuple, domain, degree, cardinality, keys (candidate key,, primary key, alternate key, foreign key), Structured Query Language: introduction, Data Definition Language and Data Manipulation, Language, data type (char(n), varchar(n), int, float, date), constraints (not null, unique, primary, key), create database, use database, show databases, drop database, show tables, create table,, describe table, alter table (add and remove an attribute, add and remove primary key), drop table,, insert, delete, select, operators (mathematical, relational and logical), aliasing, distinct clause,, where clause, in, between, order by, meaning of null, is null, is not null, like, update command,, delete command, Aggregate functions (max, min, avg, sum, count), group by, having clause, joins : Cartesian product, on two tables, equi-join and natural join, Interface of python with an SQL database: connecting SQL with Python, performing insert, update,, delete queries using cursor, display data by using fetchone(), fetchall(), rowcount, creating, database connectivity applications, , 5. Practical, S.No, 1, , 2, , 3, , Marks, , Term-1, , Term-2, , (Total 30), , (15 Marks), , (15 Marks), , Lab Test:, 1. Python program, , 8, , 6, , 2, , 2. 3 SQL Queries based on one/two table(s), 2 output, questions based on SQL queries, Report file:, Term – 1 : Minimum 15 Python programs based on Term - 1, Syllabus, Term – 2 :, Minimum 3 Python programs based on Term-2, Syllabus, SQL Queries – Minimum 5 sets using one table / two, tables., Minimum 2 programs based on Python - SQL, connectivity., Project (using concepts learnt in Classes 11 and 12), Term – 1 : Synopsis of the project to be submitted by the, students (documentation only, may not submit the code, during Term - 1), , 4, , ---, , 4, , 7, , 4, , 3, , 8, , 3, , 5, , 3, , 2, , 1, , Term - 2 : Final coding + Viva voce, (Student will be allowed to modify their Term 1 document and, submit the final executable code.), 4, , Viva voce
Page 8 :
6. Suggested Practical List:, Term-1, Python Programming, ●, ●, ●, ●, ●, ●, , ●, , Read a text file line by line and display each word separated by a #., Read a text file and display the number of vowels/consonants/uppercase/lowercase characters, in the file., Remove all the lines that contain the character 'a' in a file and write it to another file., Create a binary file with name and roll number. Search for a given roll number and display the, name, if not found display appropriate message., Create a binary file with roll number, name and marks. Input a roll number and update the marks., Write a random number generator that generates random numbers between 1 and 6 (simulates, a dice)., Create a CSV file by entering user-id and password, read and search the password for given userid., , Term-2, Python Programming, ●, , Write a Python program to implement a stack using list., , Database Management, ●, , Create a student table and insert data. Implement the following SQL commands on the student, table:, o ALTER table to add new attributes / modify data type / drop attribute, o UPDATE table to modify data, o ORDER By to display data in ascending / descending order, o DELETE to remove tuple(s), o GROUP BY and find the min, max, sum, count and average, o Joining of two tables., , ●, ●, , Similar exercise may be framed for other cases., Integrate SQL with Python by importing suitable module., , Database Management, ●, , Create a student table and insert data. Implement the following SQL commands on the student, table:, o ALTER table to add new attributes / modify data type / drop attribute, o UPDATE table to modify data, o ORDER By to display data in ascending / descending order, o DELETE to remove tuple(s), o GROUP BY and find the min, max, sum, count and average, , ●, , Similar exercise may be framed for other cases., Integrate SQL with Python by importing suitable module., , ●
Page 9 :
7. Suggested Reading Material, , , , NCERT Textbook for COMPUTER SCIENCE (Class XII), Support Materials on the CBSE website., , 8. Project, The aim of the class project is to create something that is tangible and useful using Python file handling/, Python-SQL connectivity. This should be done in groups of two to three students and should be started, by students at least 6 months before the submission deadline. The aim here is to find a real world problem, that is worthwhile to solve., Students are encouraged to visit local businesses and ask them about the problems that they are facing., For example, if a business is finding it hard to create invoices for filing GST claims, then students can do, a project that takes the raw data (list of transactions), groups the transactions by category, accounts for, the GST tax rates, and creates invoices in the appropriate format. Students can be extremely creative, here. They can use a wide variety of Python libraries to create user friendly applications such as games,, software for their school, software for their disabled fellow students, and mobile applications, of course, to do some of these projects, some additional learning is required; this should be encouraged. Students, should know how to teach themselves., The students should be sensitised to avoid plagiarism and violations of copyright issues while working on, projects. Teachers should take necessary measures for this.
Page 10 :
1, , Why to use Python:, The following are the primary factors to use python in day-to-day life:, , 1. Python is object-oriented, Structure supports such concepts as polymorphism, operation overloading and multiple, inheritance., 2. Indentation, Indentation is one of the greatest features in python, 3. It’s free (open source), Downloading python and installing python is free and easy, , 4. It’s Powerful, • Dynamic typing, • Built-in types and tools, • Library utilities, • Third party utilities (e.g. Numeric, NumPy, SciPy), • Automatic memory management, 5. It’s Portable, • Python runs virtually every major platform used today, • As long as you have a compatible python interpreter installed, python, programs will run in exactly the same manner, irrespective of platform., 6. It’s easy to use and learn, , • No intermediate compile, • Python Programs are compiled automatically to an intermediate form called byte, code, which the interpreter then reads., , • This gives python the development speed of an interpreter without the, performance loss inherent in purely interpreted languages., , • Structure and syntax are pretty intuitive and easy to grasp., 7. Interpreted Language, Python is processed at runtime by python Interpreter, , 8. Interactive Programming Language, Users can interact with the python interpreter directly for writing the programs, , 9. Straight forward syntax, The formation of python syntax is simple and straight forward which also makes it popular., , KVSRO ERNAKULAM, , 1
Page 11 :
Data types:, The data stored in memory can be of many types. For example, a student roll number is stored, as a numeric value and his or her address is stored as alphanumeric characters. Python has various, standard data types that are used to define the operations possible on them and the storage, method for each of them., Int, Float, Boolean, String, List, Variables:, Variables are nothing but reserved memory locations to store values. This means that when you, create a variable you reserve some space in memory., Based on the data type of a variable, the interpreter allocates memory and decides what can be, stored in the reserved memory. Therefore, by assigning different data types to variables, you can, store integers, decimals or characters in these variables., Rules for Python variables:, • A variable name must start with a letter or the underscore character, • A variable name cannot start with a number, • A variable name can only contain alpha-numeric characters and underscores(A-z, 0-9, and, _), , • Variable names are case-sensitive (age, Age and AGE are three different variables), Assigning Values to Variables:, Python variables do not need explicit declaration to reserve memory space. The declaration, happens automatically when you assign a value to a variable. The equal sign (=) is used to assign, values to variables., The operand to the left of the = operator is the name of the variable and the operand to the right, of the = operator is the value stored in the variable., For example −, a= 100, # an integer assignment, b = 1000.0, c = "John", print (a), print (b), print (c), , # A floating point, # A string
Page 12 :
3, This produces the following result −, 100, 1000.0, John, Multiple Assignment:, Python allows you to assign a single value to several variables simultaneously. For, example :, a=b=c=1, Here, an integer object is created with the value 1, and all three variables are assigned to the, same memory location. You can also assign multiple objects to multiple variables., For example −, a,b,c = 1,2,"kvsch“, Here, two integer objects with values 1 and 2 are assigned to variables a and b respectively, and, one string object with the value "john" is assigned to the variable c., Output Variables:, The Python print statement is often used to output variables., Variables do not need to be declared with any particular type and can even change type after, they have been set., x=5, x = "kve ", print(x), , # x is of type int, # x is now of type str, , Output: kve, To combine both text and a variable, Python uses the “+” character:, Example, x = "awesome", print("Python is " + x), Output, Python is awesome, KVSRO ERNAKULAM, , 3
Page 13 :
You can also use the + character to add a variable to another variable:, Example, x = "Python is ", y = "awesome", z=x+y, print(z), Output:, Python is awesome, Expressions:, An expression is a combination of values, variables, and operators. An expression is, evaluated using assignment operator., Examples: Y=x + 17, >>> x=10, >>> z=x+20, >>> z, 30, >>> x=10, >>> y=20, >>> c=x+y, >>> c, 30, A value all by itself is a simple expression, and so is a variable., >>> y=20, >>> y, 20, Python also defines expressions only contain identifiers, literals, and operators. So,, Identifiers: Any name that is used to define a class, function, variable module, or object is an, identifier., Literals: These are language-independent terms in Python and should exist independently in any, programming language. In Python, there are the string literals, byte literals, integer literals,, floating point literals, and imaginary literals., Operators: In Python you can implement the following operations using the corresponding, tokens.
Page 15 :
Operator, , Token, , add, , +, , subtract, , -, , multiply, , *, , Integer Division, remainder, , /, %, , Binary left shift, , <<, , Binary right shift, , >>, , and, , &, , or, , \, , Less than, , <, , Greater than, , >, , Less than or equal to, , <=, , Greater than or equal to, , >=, , Check equality, , ==, , Check not equal, , !=, , Statements:, A statement is an instruction that the Python interpreter can execute. We have normally two basic, statements, the assignment statement and the print statement. Some other kinds of statements, that are if statements, while statements, and for statements generally called as control flows., Examples:, An assignment statement creates new variables and gives them values:, >>> x=10, >>> school="kve", An print statement is something which is an input from the user, to be printed / displayed on to the, screen (or ) monitor., >>> print("kvro ernakulam"), kv roernakulam
Page 16 :
7, , Precedence of Operators:, Operator precedence affects how an expression is evaluated., For example, x = 7 + 3 * 2; here, x is assigned 13, not 20 because operator * has higher, precedence than +, so it first multiplies 3*2 and then adds into 7., Example 1:, >>> 3+4*2 11, Multiplication gets evaluated before the addition operation, >>> (10+10)*2 40, Parentheses () overriding the precedence of the arithmetic operators, Example 2:, a = 20, b = 10, c = 15, d=5, e=0, e = (a + b) * c / d, #( 30 * 15 ) / 5, print("Value of (a + b) * c / d is ", e), e = ((a + b) * c) / d, # (30 * 15 ) / 5, print("Value of ((a + b) * c) / d is ", e), e = (a + b) * (c / d);, , # (30) * (15/5), , KVSRO ERNAKULAM, , 7
Page 17 :
print("Value of (a + b) * (c / d) is ", e), e = a + (b * c) / d;, # 20 +, (150/5) print("Value of a + (b * c) / d, is ", e), Output:, Value of (a + b) * c / d is, Value of ((a + b) * c) / d, Value of (a + b) * (c / d), Value of a + (b * c) / d is, , 90.0, is 90.0, is 90.0, 50.0, , Comments:, Single-line comments begins with a hash(#) symbol and is useful in mentioning that the, whole line should be considered as a comment until the end of line., A Multi line comment is useful when we need to comment on many lines. In python, triple, double quote(“ “ “) and single quote(‘ ‘ ‘)are used for multi-line commenting., Example:, , Output:, 30, Errors and Exceptions:, Python Errors and Built-in Exceptions: Python (interpreter) raises exceptions when it, encounters errors. When writing a program, we, more often than not, will encounter, errors. Error caused by not following the proper structure (syntax) of the language is called syntax, error or parsing error, ZeroDivisionError:, ZeroDivisionError in Python indicates that the second argument used in a division (or, modulo) operation was zero.
Page 18 :
9, OverflowError:, OverflowError in Python indicates that an arithmetic operation has exceeded the limits of the, current Python runtime. This is typically due to excessively large float values, as integer values, that are too big will opt to raise memory errors instead., ImportError:, It is raised when you try to import a module which does not exist. This may happen if you made, a typing mistake in the module name or the module doesn't exist in its standard path. In the, example below, a module named "non_existing_module" is being imported but it doesn't, exist, hence an import error exception is raised., IndexError:, An IndexError exception is raised when you refer a sequence which is out of range. In the, example below, the list abc contains only 3 entries, but the 4th index is being accessed,, which will result an IndexError exception., TypeError:, When two unrelated type of objects are combined, TypeErrorexception is raised.In example, below, an int and a string is added, which will result in TypeError exception., IndentationError:, Unexpected indent. As mentioned in the "expected an indentedblock" section, Python not only, insists on indentation, it insists on consistentindentation. You are free to choose the number, of spaces of indentation to use, but you then need to stick with it., Syntax errors:, These are the most basic type of error. They arise when the Python parser is unable to, understand a line of code. Syntax errors are almost always fatal, i.e. there is almost never a, way to successfully execute a piece of code containing syntax errors., Run-time error:, A run-time error happens when Python understands what you are saying, but runs into trouble, when following your instructions., Key Error :, Python raises a KeyError whenever a dict() object is requested (using the format a, = adict[key]) and the key is not in the dictionary., , KVSRO ERNAKULAM, , 9
Page 19 :
Value Error:, In Python, a value is the information that is stored within a certain object. To encounter a, ValueError in Python means that is a problem with the content of the object you tried to, assign the value to., , Python has many built-in exceptions which forces your program to output an error when, something in it goes wrong. In Python, users can define such exceptions by creating a new, class. This exception class has to be derived, either directly or indirectly, from, Exception class., Different types of exceptions:, , •, •, •, •, •, •, •, , ArrayIndexOutOfBoundException., ClassNotFoundException., FileNotFoundException., IOException., InterruptedException., NoSuchFieldException., NoSuchMethodException, , Modules:, Modules: Python module can be defined as a python program file which contains a python code, including python functions, class, or variables. In other words, we can say that our python, code file saved with the extension (.py) is treated as the module. We may have a runnable, code inside the python module. A module in Python provides us the flexibility to organize the, code in a logical way. To use the functionality of one module into another, we must have to, import the specific module., Syntax:, import <module-name>, Every module has its own functions, those can be accessed with . (dot), Note: In python we have help (), Enter the name of any module, keyword, or topic to get help on writing Python programs and, using Python modules. To quit this help utility and return to the interpreter, just type "quit"., Some of the modules like os, date, and calendar so on……, >>> import sys, >>> print (sys.version), 3.8.0 (tags/v3.8.0:fa919fd, Oct 14 2019, 19:21:23) [MSC v.1916 32 bit (Intel)], >>> print(sys.version_info)
Page 21 :
Control Flow, Loops:, , Conditional (if):, The if statement contains a logical expression using which data is compared and a decision is, made based on the result of the comparison., Syntax:, if expression:, statement(s), If the boolean expression evaluates to TRUE, then the block of statement(s) inside the if, statement is executed. If boolean expression evaluates to FALSE, then the first set of code, after the end of the if statement(s) is executed., if Statement Flowchart:, , Fig: Operation of if statement, Example: Python if Statement, a=3, if a > 2:, print(a, "is greater"), print("done"), a = -1, if a < 0:, print(a, "a is smaller"), print("Finish")
Page 22 :
13, Output:, 3 is greater, done, -1 a is smaller, Finish, -------------------------------- a=10, if a>9:, print("A is Greater than 9"), Output:, A is Greater than 9, Alternative if (If-Else):, An else statement can be combined with an if statement. An else statement contains the block, of code (false block) that executes if the conditional expression in the if statement resolves to, 0 or a FALSE value., The else statement is an optional statement and there could be at most only one else, Statement following if., Syntax of if - else :, if test expression:, Body of if stmts, else:, Body of else stmts, If - else Flowchart :, , KVSRO ERNAKULAM, , 13
Page 23 :
Fig: Operation of if – else statement
Page 24 :
15, , Example of if - else:, a=int(input('enter the number')) if, a>5:, print("a is greater") else:, print("a is smaller than the input given"), Output:, enter the number 2, a is smaller than the input given, ---------------------------------------a=10, b=20, if a>b:, print("A is Greater than B"), else:, print("B is Greater than A"), Output:, B is Greater than A, Chained Conditional: (If-elif-else):, The elif statement allows us to check multiple expressions for TRUE and execute a block, of code as soon as one of the conditions evaluates to TRUE. Similar to the else, the elif, statement is optional. However, unlike else, for which there can be at most one statement,, there can be an arbitrary number of elif statements following an if., Syntax of if – elif - else :, If test expression:, Body of if stmts elif, test expression:, Body of elif stmts, else:, Body of else stmts, , KVSRO ERNAKULAM, , 15
Page 25 :
Flowchart of if – elif - else:, , Fig: Operation of if – elif - else statement, Example of if - elif – else:, a=int(input('enter the number')), b=int(input('enter the number')), c=int(input('enter the number')), if a>b:print("a is greater"), elif b>c:, print("b is greater"), else:, print("c is greater"), Output:, enter the number5, enter the number2, enter the number9, a is greater, >>>, enter the number2, enter the number5, enter the number9, c is greater, ----------------------------var = 100, if var == 200:, print("1 - Got a true expression value"), print(var), elif var == 150:, print("2 - Got a true expression value"), print(var), elif var == 100:, print("3 - Got a true expression value")
Page 26 :
17, print(var), else:, print("4 - Got a false expression value"), print(var), print("Good bye!"), Output:, 3 - Got a true expression value, 100, Good bye!, , KVSRO ERNAKULAM, , 17
Page 27 :
Iteration:, A loop statement allows us to execute a statement or group of statements multiple times as long, as the condition is true. Repeated execution of a set of statements with the help of loops is called, iteration., Loops statements are used when we need to run same code again and again, each time with a, different value., Statements:, In Python Iteration (Loops) statements are of three types:, 1. While Loop, 2. For Loop, 3. Nested For Loops, While loop:, , • Loops are either infinite or conditional. Python while loop keeps reiterating a block of code, defined inside it until the desired condition is met., , • The while loop contains a boolean expression and the code inside the loop is, repeatedly executed as long as the boolean expression is true., , • The statements that are executed inside while can be a single line of code or a block of, multiple statements., Syntax:, while(expression):, Statement(s), Flowchart:
Page 28 :
19, Example Programs:, 1. -------------------------------------i=1, while i<=6:, print("KV School") i=i+1, output:, KV School, KV School, KV School, KV School, KV School, KV School, 2., , ----------------------------------------------------i=1, while i<=3:, print("KV School",end=" "), j=1, while j<=1:, print("CS DEPT",end=""), j=j+1, i=i+1, print(), , Output:, KV School CS DEPT, KV School CS DEPT, KV School CS DEPT, , KVSRO ERNAKULAM, , 19
Page 29 :
For loop:, Python for loop is used for repeated execution of a group of statements for the desired, number of times. It iterates over the items of lists, tuples, strings, the dictionaries and other, iterable objects, Syntax: for var in sequence:, Statement(s), Holds the value of item, in sequence in each iteration, Sample Program:, numbers = [1, 2, 4, 6, 11, 20], seq=0, for val in numbers:, seq=val*val print(seq), Output:, 1, 4, 16, 36, 121, 400, Flowchart:, , A sequence of values assigned to var in each iteration
Page 30 :
21, Iterating over a list:, #list of items, list = ['K','V','S','C','H'], i=1, #Iterating over the list, for item in list:, print ('School ',i,' is ',item), i = i+1, Output:, School, School, School, School, School, , 1, 2, 3, 4, 5, , is, is, is, is, is, , K, V, S, C, H, , Iterating over a Tuple:, tuple = (2,3,5,7), print ('These are the first four prime numbers '), #Iterating over the tuple, for a in tuple:, print (a), Output:, These are the first four prime numbers, 2, 3, 5, 7, Iterating over a dictionary:, #creating a dictionary, college = {"ces":"block1","it":"block2","ece":"block3"}, #Iterating over the dictionary to print keys, print ('Keys are:'), , KVSRO ERNAKULAM, , 21
Page 31 :
for keys in college:, print (keys), #Iterating over the dictionary to print values, print ('Values are:'), for blocks in college.values():, print(blocks), Output:, Keys are:, ces, it, ece, Values are:, block1, block2, block3, Iterating over a String:, #declare a string to iterate over, college = 'KVSCH', #Iterating over the string, for name in college:, print (name), Output:, K, V, S, C, H, Nested For loop:, When one Loop defined within another Loop is called Nested Loops., Syntax:, for val in sequence:, for val in sequence:, statements, statements
Page 32 :
23, # Example 1 of Nested For Loops (Pattern Programs), for i in range(1,6): for, j in range(0,i):, print(i, end=" "), print(''), Output:, 1, 22, 333, 4444, 55555, -------------------------# Example 2 of Nested For Loops (Pattern Programs), for i in range(1,6):, for j in range(5,i-1,-1):, print(i, end=" "), print(''), Output:, 11111, 2222, 333, 44, , KVSRO ERNAKULAM, , 23
Page 33 :
Break and continue:, In Python, break and continue statements can alter the flow of a normal loop. Sometimes we, wish to terminate the current iteration or even the whole loop without checking test expression., The break and continue statements are used in these cases., Break:, The break statement terminates the loop containing it and control of the program flows to the, statement immediately after the body of the loop. If break statement is inside a nested loop (loop, inside another loop), break will terminate the innermost loop., Continue:, The continue statement is used to skip the rest of the code inside a loop for the current iteration, only. Loop does not terminate but continues on with the next iteration., Pass:, In Python programming, pass is a null statement. The difference between a, comment and pass statement in Python is that, while the interpreter ignores a comment, entirely, pass is not ignored. Pass is just a placeholder for functionality to be added later., , Strings:, A string is a group/ a sequence of characters. Since Python has no provision for arrays, we, simply use strings. This is how we declare a string. We can use a pair of single or double, quotes. Every string object is of the type ‘str’., >>> type("name"), <class 'str'>, >>> name=str(), >>>, name '', >>> a=str('kvsch'), >>> a, ' kvsch', >>> a=str(kvsch), >>> a[2], 's', >>> fruit = 'banana', >>> letter = fruit[1], The second statement selects character number 1 from fruit and assigns it to letter. The, expression in brackets is called an index. The index indicates which character in the, sequence we want
Page 34 :
25, String slices:, A segment of a string is called a slice. Selecting a slice is similar to selecting a character:, Subsets of strings can be taken using the slice operator ([ ] and [:]) with indexes starting at 0 in, the beginning of the string and working their way from -1 at the end., Slice out substrings, sub lists, sub Tuples using index., Syntax:[Start: stop: steps], • Slicing will start from index and will go up to stop in step of steps., , • Default value of start is 0,, • Stop is last index of list, • And for step default is 1, For example 1:, str = 'Hello World!', print (str) # Prints complete string, print (str[0] )# Prints first character of the string, print (str[2:5] ) # Prints characters starting from 3rd to 5th, print (str[2:]) # Prints string starting from 3rd character, print ( str * 2 )# Prints string two times, print (str + "TEST") # Prints concatenated string, Output:, Hello World! H, llo, llo World!, Hello World!Hello World!, Hello World!TEST, Example 2:, >>> x='computer', >>> x[1:4], 'omp', >>> x[1:6:2], 'opt', >>> x[3:], , KVSRO ERNAKULAM, , 25
Page 35 :
'puter', >>> x[:5], 'compu', >>> x[-1], 'r', >>> x[-3:], 'ter', >>> x[:-2], 'comput', >>> x[::-2], 'rtpo', >>> x[::-1], 'retupmoc', Immutability:, It is tempting to use the [] operator on the left side of an assignment, with the intention of, changing a character in a string., For example:, >>> greeting='kvsch school!', >>> greeting[0]='n', TypeError: 'str' object does not support item assignment, The reason for the error is that strings are immutable, which means we can’t change an, existing string. The best we can do is creating a new string that is a variation on the original:, >>> greeting = 'Hello, world!', >>> new_greeting = 'J' + greeting[1:], >>> new_greeting, 'Jello, world!', Note: The plus (+) sign is the string concatenation operator and the asterisk (*) is the, repetition operator
Page 36 :
27, String functions and methods:, There are many methods to operate on String., S.no, 1., , Method name, isalnum(), , 2., , isalpha(), , 3., , isdigit(), , 4., , islower(), , 5., , isnumeric(), , 6., , isspace(), , 7., , istitle(), , 8., , isupper(), , 9., , replace(old, new, [, max]), , 10. split(), 11. count(), 12. find(), 13. swapcase(), 14. startswith(str,, beg=0,end=le, n(string)), , Description, Returns true if string has at least 1 character and all, characters are alphanumeric and false otherwise., Returns true if string has at least 1 character and all, characters are alphabetic and false otherwise., Returns true if string contains only digits and false, otherwise., Returns true if string has at least 1 cased character and all cased, characters are in lowercase and false, otherwise., Returns true if a string contains only numeric, characters and false otherwise., Returns true if string contains only whitespace, characters and false otherwise., Returns true if string is properly “titlecased” and, false otherwise., Returns true if string has at least one cased character and all, cased characters are in uppercase, and false otherwise., Replaces all occurrences of old in string with new or, at most max occurrences if max given., Splits string according to delimiter str (space if not, provided) and returns list of substrings;, Occurrence of a string in another string, Finding the index of the first occurrence of a string in, another string, Converts lowercase letters in a string to uppercase, and viceversa, Determines if string or a substring of string (if starting index beg, and ending index end are given) starts with substring str; returns, true if so and false, otherwise., , KVSRO ERNAKULAM, , 27
Page 37 :
Output:, 30, , Array methods:, Python has a set of built-in methods that you can use on lists/arrays., Method, , Description, , append(), , Adds an element at the end of the list, , clear(), , Removes all the elements from the list, , copy(), , Returns a copy of the list, , count(), , Returns the number of elements with the specified value, , extend(), , Add the elements of a list (or any iterable), to the end of the current list, , index(), , Returns the index of the first element with the specified value, , insert(), , Adds an element at the specified position, , pop(), , Removes the element at the specified position, , remove(), , Removes the first item with the specified value, , reverse(), , Reverses the order of the list, , sort(), , Sorts the list, , Note: Python does not have built-in support for Arrays, but Python Lists can be used instead.
Page 38 :
29, LISTS, TUPLES, DICTIONARIES, Lists: list operations, list slices, list methods, list loop, mutability, aliasing, cloning lists, list, parameters, list comprehension; Tuples: tuple assignment, tuple as return value, tuple, comprehension; Dictionaries: operations and methods, comprehension;, Lists, Tuples, Dictionaries:, List:, , • It is a general purpose most widely used in data structures, • List is a collection which is ordered and changeable and allows duplicate members., (Grow and shrink as needed, sequence type, sortable)., , • To use a list, you must declare it first. Do this using square brackets and separate, values with commas., , • We can construct / create list in many ways., Ex:, >>> list1=[1,2,3,'A','B',7,8,[10,11]], >>> print(list1), [1, 2, 3, 'A', 'B', 7, 8, [10, 11]], --------------------->>> x=list(), >>>, x [], ------------------------->>> tuple1=(1,2,3,4), >>> x=list(tuple1), >>> x, [1, 2, 3, 4], List operations:, These operations include, for membership, , indexing,, , slicing,, , adding,, , multiplying,, , and, , checking, , Basic List Operations:, Lists respond to the + and * operators much like strings; they mean concatenation and, repetition here too, except that the result is a new list, not a string., Python Expression, , Results, , Description, KVSRO ERNAKULAM, , 29
Page 39 :
len([1, 2, 3]), , 3, , Length, , [1, 2, 3] + [4, 5, 6], , [1, 2, 3, 4, 5, 6], , Concatenation, , ['Hi!'] * 4, , ['Hi!', 'Hi!', 'Hi!', 'Hi!'], , 3 in [1, 2, 3], for x in [1, 2, 3]: print x,, , Repetition, , True, , Membership, , 123, , Iteration, , Indexing, Slicing, and Matrixes, Because lists are sequences, indexing and slicing work the same way for lists as they do for, strings., Assuming following input −, L = ['kvsch', 'school', 'KVSCH!'], Python Expression, , Results, , L[2], , KVSCH, , L[-2], , school, , L[1:], , List slices:, >>> list1=range(1,6), >>> list1, range(1, 6), >>> print(list1), range(1, 6), >>> list1= [1,2,3,4,5,6,7,8,9,10], >>> list1[1:], [2, 3, 4, 5, 6, 7, 8, 9, 10], >>> list1[:1], [1], >>> list1[2:5] [3,, 4, 5], >>> list1[:6] [1,, 2, 3, 4, 5, 6], >>> list1[1:2:4], [2], >>> list1[1:8:2], [2, 4, 6, 8], , ['school', 'KVSCH!'], , Description, Offsets start at zero, Negative: count from the right, Slicing fetches sections
Page 40 :
31, , List methods:, The list data type has some more methods. Here are all of the methods of list objects:, , •, •, •, •, •, •, •, •, , Del(), Append(), Extend(), Insert(), Pop(), Remove(), Reverse(), Sort(), , Delete: Delete a list or an item from a list, >>> x=[5,3,8,6], >>> del(x[1]), , #deletes the index position 1 in a list, , >>> x [5,, 8, 6], ----------->>> del(x), >>> x, , # complete list gets deleted, , Append: Append an item to a list, >>> x=[1,5,8,4], >>> x.append(10), >>> x, [1, 5, 8, 4, 10], Extend: Append a sequence to a list., >>> x=[1,2,3,4], >>> y=[3,6,9,1], >>> x.extend(y), KVSRO ERNAKULAM, , 31
Page 41 :
>>> x, [1, 2, 3, 4, 3, 6, 9, 1], Insert: To add an item at the specified index, use the insert () method:, >>> x=[1,2,4,6,7]
Page 42 :
33, >>> x.insert(2,10), , #insert(index no, item to be inserted), , >>> x, [1, 2, 10, 4, 6, 7], ------------------------>>> x.insert(4,['a',11]), >>> x, [1, 2, 10, 4, ['a', 11], 6, 7], Pop: The pop() method removes the specified index, (or the last item if index is not, specified) or simply pops the last item of list and returns the item., >>> x=[1, 2, 10, 4, 6, 7], >>> x.pop() 7, >>> x, [1, 2, 10, 4, 6], ---------------------------------->>> x=[1, 2, 10, 4, 6], >>> x.pop(2), 10, >>> x, [1, 2, 4, 6], Remove: The remove() method removes the specified item from a given list., >>> x=[1,33,2,10,4,6], >>> x.remove(33), >>> x, , KVSRO ERNAKULAM, , 33
Page 43 :
[1, 2, 10, 4, 6], >>> x.remove(4), >>> x, [1, 2, 10, 6], Reverse: Reverse the order of a given list., >>> x=[1,2,3,4,5,6,7], >>> x.reverse(), >>> x, [7, 6, 5, 4, 3, 2, 1], Sort: Sorts the elements in ascending order, >>> x=[7, 6, 5, 4, 3, 2, 1], >>> x.sort(), >>> x, [1, 2, 3, 4, 5, 6, 7], ---------------------->>> x=[10,1,5,3,8,7], >>> x.sort(), >>> x, [1, 3, 5, 7, 8, 10], List loop:, Loops are control structures used to repeat a given section of code a certain number of times or, until a particular condition is met., Method #1: For loop, #list of items, list = ['K','V','S','C','H']
Page 44 :
35, i=1, #Iterating over the list, for item in list:, print ('school ',i,' is ',item), i = i+1, Output:, school, school, school, school, school, , 1 is K, 2 is V, 3 is S, 4 is C, 5 is H, , Method #2: For loop and range (), In case we want to use the traditional for loop which iterates from number x to number y., # Python3 code to iterate over a list, list = [1, 3, 5, 7, 9], # getting length of list, length = len(list), # Iterating the index, # same as 'for i in range(len(list))', for i in range(length):, print(list[i]), Output:, 3, 5, 7, 9, Method #3: using while loop, # Python3 code to iterate over a list, list = [1, 3, 5, 7, 9], # Getting length of list, length = len(list) i = 0, # Iterating using while loop while, i < length:, print(list[i]) i, += 1, KVSRO ERNAKULAM, , 35
Page 45 :
Mutability:, A mutable object can be changed after it is created, and an immutable object can't., Append: Append an item to a list, >>> x=[1,5,8,4], >>> x.append(10), >>> x, [1, 5, 8, 4, 10], Extend: Append a sequence to a list., >>> x=[1,2,3,4], >>> y=[3,6,9,1], >>> x.extend(y), >>> x, Delete: Delete a list or an item from a list, >>> x=[5,3,8,6], >>> del(x[1]), , #deletes the index position 1 in a list, , >>> x [5,, 8, 6], Insert: To add an item at the specified index, use the insert () method:, >>> x=[1,2,4,6,7], >>> x.insert(2,10), , #insert(index no, item to be inserted)
Page 46 :
37, >>> x, [1, 2, 10, 4, 6, 7], ------------------------>>> x.insert(4,['a',11]), >>> x, [1, 2, 10, 4, ['a', 11], 6, 7], Pop: The pop() method removes the specified index, (or the last item if index is not, specified) or simply pops the last item of list and returns the item., >>> x=[1, 2, 10, 4, 6, 7], >>> x.pop() 7, >>> x, [1, 2, 10, 4, 6], ---------------------------------->>> x=[1, 2, 10, 4, 6], >>> x.pop(2), 10, >>> x, [1, 2, 4, 6], Remove: The remove() method removes the specified item from a given list., >>> x=[1,33,2,10,4,6], >>> x.remove(33), >>> x, [1, 2, 10, 4, 6], , KVSRO ERNAKULAM, , 37
Page 47 :
>>> x.remove(4), >>> x, [1, 2, 10, 6], Reverse: Reverse the order of a given list., >>> x=[1,2,3,4,5,6,7], >>> x.reverse(), >>> x, [7, 6, 5, 4, 3, 2, 1], Sort: Sorts the elements in ascending order, >>> x=[7, 6, 5, 4, 3, 2, 1], >>> x.sort(), >>> x, [1, 2, 3, 4, 5, 6, 7], ---------------------->>> x=[10,1,5,3,8,7], >>> x.sort(), >>> x, [1, 3, 5, 7, 8, 10], , Aliasing:, , 1. An alias is a second name for a piece of data, often easier (and more useful) than, making a copy., 2. If the data is immutable, aliases don’t matter because the data can’t change., 3. But if data can change, aliases can result in lot of hard – to – find bugs., 4. Aliasing happens whenever one variable’s value is assigned to another variable., For ex:, a = [81, 82, 83]
Page 48 :
39, b = [81, 82, 83], print(a == b), print(a is b) b, =a, print(a == b), print(a is b), b[0] = 5, print(a), Output:, False, True, True, [5, 82, 83], Because the same list has two different names, a and b, we say that it is aliased. Changes, made with one alias affect the other. In the example above, you can see that a and b refer to the, same list after executing the assignment statement b = a., Cloning Lists:, If we want to modify a list and also keep a copy of the original, we need to be able to make a copy, of the list itself, not just the reference. This process is sometimes called cloning, to avoid the, ambiguity of the word copy., The easiest way to clone a list is to use the slice operator. Taking any slice of a creates a new list., In this case the slice happens to consist of the whole list., Example:, a = [81, 82, 83], b = a[:], , # make a clone using slice, , print(a == b), print(a is b), b[0] = 5, print(a), print(b), , KVSRO ERNAKULAM, , 39
Page 49 :
Output:, True, False, [81, 82, 83], [5, 82, 83], Now we are free to make changes to b without worrying about a, , List parameters:, Passing a list as an argument actually passes a reference to the list, not a copy of the list. Since, lists are mutable, changes made to the elements referenced by the parameter change the same, list that the argument is referencing., # for example, the function below takes a list as an argument and multiplies each element in the, list by 2:, def doubleStuff(List):, """ Overwrite each element in aList with double its value. """ for, position in range(len(List)):, List[position] = 2 * List[position], , things = [2, 5, 9], print(things), doubleStuff(things), print(things), Output:, [2, 5, 9], [4, 10, 18]
Page 50 :
41, List comprehension:, List:, List comprehensions provide a concise way to create lists. Common applications are to make new, lists where each element is the result of some operations applied to each member of another, sequence or iterable, or to create a subsequence of those elements that satisfy a certain, condition., For example, assume we want to create a list of squares, like:, >>> list1=[], >>> for x in range(10):, list1.append(x**2), >>> list1, [0, 1, 4, 9, 16, 25, 36, 49, 64, 81], (or), This is also equivalent to, >>> list1=list(map(lambda x:x**2, range(10))), >>> list1, [0, 1, 4, 9, 16, 25, 36, 49, 64, 81], (or), Which is more concise and readable., >>> list1=[x**2 for x in range(10)], >>> list1, [0, 1, 4, 9, 16, 25, 36, 49, 64, 81], , KVSRO ERNAKULAM, , 41
Page 51 :
Similarily some examples:, >>> x=[m for m in range(8)], >>> print(x), [0, 1, 2, 3, 4, 5, 6, 7], >>> x=[z**2 for z in range(10) if z>4], >>> print(x), [25, 36, 49, 64, 81], >>> x=[x ** 2 for x in range (1, 11), >>> print(x), [1, 9, 25, 49, 81], , if x % 2 == 1], , >>> a=5, >>> table = [[a, b, a * b] for b in range(1, 11)], >>> for i in table:, print(i), , [5, 1, 5], [5, 2, 10], [5, 3, 15], [5, 4, 20], [5, 5, 25], [5, 6, 30], [5, 7, 35], [5, 8, 40], [5, 9, 45], [5, 10, 50], , Tuples:, A tuple is a collection which is ordered and unchangeable. In Python tuples are written with, round brackets., , • Supports all operations for sequences., • Immutable, but member objects may be mutable., • If the contents of a list shouldn’t change, use a tuple to prevent items from
Page 52 :
43, accidently being added, changed, or deleted., , • Tuples are more efficient than list due to python’s implementation., We can construct tuple in many ways:, X=(), #no item tuple, X=(1,2,3), X=tuple(list1), X=1,2,3,4, Example:, >>> x=(1,2,3), >>> print(x), (1, 2, 3), >>> x (1,, 2, 3), ---------------------->>> x=(), >>> x, (), --------------------------->>> x=[4,5,66,9], >>> y=tuple(x), >>> y, (4, 5, 66, 9), ---------------------------->>> x=1,2,3,4, >>> x, (1, 2, 3, 4), Some of the operations of tuple are:, , •, •, •, •, •, •, , Access tuple items, Change tuple items, Loop through a tuple, Count(), Index(), Length(), , KVSRO ERNAKULAM, , 43
Page 53 : Access tuple items: Access tuple items by referring to the index number, inside square, brackets, >>> x=('a','b','c','g'), >>> print(x[2]) c, Change tuple items: Once a tuple is created, you cannot change its values. Tuples are, unchangeable., >>> x=(2,5,7,'4',8), >>> x[1]=10, Traceback (most recent call last):, File "<pyshell#41>", line 1, in <module> x[1]=10, TypeError: 'tuple' object does not support item assignment, >>> x, (2, 5, 7, '4', 8), # the value is still the same, Loop through a tuple: We can loop the values of tuple using for loop, >>> x=4,5,6,7,2,'aa', >>> for i in x:, print(i), , 4, 5, 6, 7, 2, aa, Count (): Returns the number of times a specified value occurs in a tuple, >>> x=(1,2,3,4,5,6,2,10,2,11,12,2), >>> x.count(2) 4, Index (): Searches the tuple for a specified value and returns the position of where it was, found
Page 54 :
45, >>> x=(1,2,3,4,5,6,2,10,2,11,12,2), >>> x.index(2) 1, (Or), >>> x=(1,2,3,4,5,6,2,10,2,11,12,2), >>> y=x.index(2), >>> print(y) 1, Length (): To know the number of items or values present in a tuple, we use len()., >>> x=(1,2,3,4,5,6,2,10,2,11,12,2), >>> y=len(x), >>> print(y) 12, , Tuple Assignment, Python has tuple assignment feature which enables you to assign more than one variable at a time., In here, we have assigned tuple 1 with the college information like college name, year, etc. and, another tuple 2 with the values in it like number (1, 2, 3… 7)., For Example,, Here is the code,, >>> tup1 = ('kvsch', 'eng college','2004','cse', 'it','csit');, >>> tup2 = (1,2,3,4,5,6,7);, >>> print(tup1[0]), •, , kvsch, >>> print(tup2[1:4]), (2, 3, 4), , Tuple 1 includes list of information of kvsch, Tuple 2 includes list of numbers in it, , KVSRO ERNAKULAM, , 45
Page 55 :
We call the value for [0] in tuple and for tuple 2 we call the value between 1 and 4, Run the above code- It gives name kvsch for first tuple while for second tuple it gives, number (2, 3, 4), Tuple as return values:, A Tuple is a comma separated sequence of items. It is created with or without (). Tuples are, immutable., # A Python program to return multiple values from a method using tuple, # This function returns a tuple, def fun():, str = "kvsch college", x = 20, return str, x; # Return tuple, we could also, # write (str, x), # Driver code to test above method str,, x = fun() # Assign returned tuple, print(str), print(x), Output:, 20, , • Functions can return tuples as return values., def circleInfo(r):, """ Return (circumference, area) of a circle of radius r """ c = 2, * 3.14159 * r, a = 3.14159 * r * r, return (c, a), print(circleInfo(10)), Output:, (62.8318, 314.159)
Page 56 :
47, -----------------------------def f(x):, y0 = x + 1, y1 = x * 3, y2 = y0 ** y3 return, (y0, y1, y2), Tuple comprehension:, Tuple Comprehensions are special: The result of a tuple comprehension is special. You might, expect it to produce a tuple, but what it does is produce a special "generator" object that, we can iterate over., For example:, >>> x = (i for i in 'abc') #tuple comprehension, >>> x, <generator object <genexpr> at 0x033EEC30>, >>> print(x), <generator object <genexpr> at 0x033EEC30>, You might expect this to print as ('a', 'b', 'c') but it prints as <generator object <genexpr> at, 0x02AAD710> The result of a tuple comprehension is not a tuple: it is actually a generator., The only thing that you need to know now about a generator now is that you can iterate over, it, but ONLY ONCE., So, given the code, >>> x = (i for i in 'abc'), >>> for i in x:, print(i), a, b, c, Create a list of 2-tuples like (number, square):, >>> z=[(x, x**2) for x in range(6)], >>> z, [(0, 0), (1, 1), (2, 4), (3, 9), (4, 16), (5, 25)], , KVSRO ERNAKULAM, , 47
Page 57 :
Set:, Similarly to list comprehensions, set comprehensions are also supported:, >>> a = {x for x in 'abracadabra' if x not in 'abc'}, >>> a, {'r', 'd'}, >>> x={3*x for x in range(10) if x>5}, >>> x, {24, 18, 27, 21}, Dictionaries:, A dictionary is a collection which is unordered, changeable and indexed. In Python, dictionaries are written with curly brackets, and they have keys and values., , • Key-value pairs, • Unordered, We can construct or create dictionary like: X={1:’A’,2:’B’,3:’c’}, X=dict([(‘a’,3) (‘b’,4)], X=dict(‘A’=1,’B’ =2), Example:, >>> dict1 = {"brand":"mrcet","model":"college","year":2004}, >>> dict1, {'brand': 'mrcet', 'model': 'college', 'year': 2004}, Operations and methods:, Methods that are available with dictionary are tabulated below. Some of them have already been, used in the above examples., , Method, clear(), , Description, Remove all items form the dictionary.
Page 58 :
49, , copy(), , Return a shallow copy of the dictionary., , fromkeys(seq[, v]), , Return a new dictionary with keys from seq and value, equal to v (defaults to None)., , get(key[,d]), , Return the value of key. If key does not exit, return, d (defaults to None)., , items(), , Return a new view of the dictionary's items (key,, value)., , keys(), , Return a new view of the dictionary's keys., , pop(key[,d]), , Remove the item with key and return its value or d if, key is not found. If d is not provided and key is not, found, raises KeyError., , popitem(), , Remove and return an arbitary item (key, value)., Raises KeyError if the dictionary is empty., , setdefault(key[,d]), , If key is in the dictionary, return its value. If not,, insert key with a value of d and, return d (defaults to None)., , update([other]), , Update the dictionary with the key/value pairs from, other, overwriting existing keys., , values(), , Return a new view of the dictionary's values, , Below are some dictionary operations:, , KVSRO ERNAKULAM, , 49
Page 59 :
To access specific value of a dictionary, we must pass its key,, >>> dict1 = {"brand":"mrcet","model":"college","year":2004}, >>> x=dict1["brand"], >>> x, 'mrcet', --------------------To access keys and values and items of dictionary:, >>> dict1 = {"brand":"mrcet","model":"college","year":2004}, >>> dict1.keys() dict_keys(['brand',, 'model', 'year']), >>> dict1.values() dict_values(['mrcet',, 'college', 2004]), >>> dict1.items(), dict_items([('brand', 'mrcet'), ('model', 'college'), ('year', 2004)]), ---------------------------------------------->>> for items in dict1.values(): print(items), , mrcet, college, 2004, >>> for items in dict1.keys(): print(items), , brand, model, year, >>> for i in dict1.items():, print(i), , ('brand', 'mrcet'), ('model', 'college'), ('year', 2004), Some more operations like:, • Add/change
Page 60 :
51, , • Remove, • Length, • Delete, Add/change values: You can change the value of a specific item by referring to its key name, >>> dict1 = {"brand":"mrcet","model":"college","year":2004}, >>> dict1["year"]=2005, >>> dict1, {'brand': 'mrcet', 'model': 'college', 'year': 2005}, Remove(): It removes or pop the specific item of dictionary., >>> dict1 = {"brand":"mrcet","model":"college","year":2004}, >>> print(dict1.pop("model")), college, >>> dict1, {'brand': 'mrcet', 'year': 2005}, Delete: Deletes a particular item., >>> x = {1:1, 2:4, 3:9, 4:16, 5:25}, >>> del x[5], >>> x, Length: we use len() method to get the length of dictionary., >>>{1: 1, 2: 4, 3: 9, 4: 16}, {1: 1, 2: 4, 3: 9, 4: 16}, >>> y=len(x), >>> y, 4, Iterating over (key, value) pairs:, >>> x = {1:1, 2:4, 3:9, 4:16, 5:25}, >>> for key in x:, print(key, x[key]), , 11, 24, 39, , KVSRO ERNAKULAM, , 51
Page 61 :
4 16, 5 25, >>> for k,v in x.items():, print(k,v), , 11, 24, 39, 4 16, 5 25, List of Dictionaries:, >>> customers = [{"uid":1,"name":"John"},, {"uid":2,"name":"Smith"},, {"uid":3,"name":"Andersson"},, ], >>> >>> print(customers), [{'uid': 1, 'name': 'John'}, {'uid': 2, 'name': 'Smith'}, {'uid': 3, 'name': 'Andersson'}], ## Print the uid and name of each customer, >>> for x in customers: print(x["uid"],, x["name"]), , 1 John, 2 Smith, 3 Andersson, ## Modify an entry, This will change the name of customer 2 from Smith to Charlie, >>> customers[2]["name"]="charlie", >>> print(customers), [{'uid': 1, 'name': 'John'}, {'uid': 2, 'name': 'Smith'}, {'uid': 3, 'name': 'charlie'}], ## Add a new field to each entry, >>> for x in customers:, x["password"]="123456" # any initial value, , >>> print(customers)
Page 62 :
53, [{'uid': 1, 'name': 'John', 'password': '123456'}, {'uid': 2, 'name': 'Smith', 'password': '123456'},, {'uid': 3, 'name': 'charlie', 'password': '123456'}], ## Delete a field, >>> del customers[1], >>> print(customers), [{'uid': 1, 'name': 'John', 'password': '123456'}, {'uid': 3, 'name': 'charlie', 'password':, '123456'}], >>> del customers[1], >>> print(customers), [{'uid': 1, 'name': 'John', 'password': '123456'}], ## Delete all fields, >>> for x in customers: del, x["uid"], , >>> x, {'name': 'John', 'password': '123456'}, Comprehension:, Dictionary comprehensions can be used to create dictionaries from arbitrary key and value, expressions:, >>> z={x: x**2 for x in (2,4,6)}, >>> z, {2: 4, 4: 16, 6: 36}, >>> dict11 = {x: x*x for x in range(6)}, >>> dict11, {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25}, , KVSRO ERNAKULAM, , 53
Page 63 :
MCQ, SECTION A, , 1. Which of the following is not a keyword?, a) eval, b) assert, c) nonlocal, d) pass, Answer: a, Explanation: eval can be used as a variable., 2. What is the order of precedence in python?, i) Parentheses, ii) Exponential, iii) Multiplication, iv) Division, v) Addition, vi) Subtraction, a) i,ii,iii,iv,v,vi, b) ii,i,iii,iv,v,vi, c) ii,i,iv,iii,v,vi, d) i,ii,iii,iv,vi,v, Answer: a, Explanation: For order of precedence, just remember this PEMDAS (similar to BODMAS)., 3.What error occurs when you execute the following Python code snippet?, apple = mango, a) SyntaxError, b) NameError, c) ValueError, d) TypeError, Answer: b, Explanation: Mango is not defined hence name error., 4. What will be the output of the following Python code snippet?, 1., def example(a):, 2., a = a + '2', 3., a = a*2, 4., return a, 5., >>>example("hello"), a) indentation Error, b) cannot perform mathematical operation on strings
Page 64 :
55, , c) hello2, d) hello2hello2, Answer: a, Explanation: Python codes have to be indented properly., 5. What will be the value of X in the following Python expression?, X = 2+9*((3*12)-8)/10 a), 30.0, b) 30.8, c) 28.4, d) 27.2, Answer: d, Explanation: The expression shown above is evaluated as: 2+9*(36-8)/10, which simplifies to, give 2+9*(2.8), which is equal to 2+25.2 = 27.2. Hence the result of this expression is 27.2., , 6. Select all options that print., hello-how-are-you, a) print(‘hello’, ‘how’, ‘are’, ‘you’), b) print(‘hello’, ‘how’, ‘are’, ‘you’ + ‘-‘ * 4), c) print(‘hello-‘ + ‘how-are-you’), d) print(‘hello’ + ‘-‘ + ‘how’ + ‘-‘ + ‘are’ + ‘you’), Answer: c, Explanation: Execute in the shell., 7. Which of the following can be used as valid variable identifier(s) in Python?, a) total, b) 7Salute, c) Que$tion, d) global, Answer: a, 8. Which of the following statement is correct for an operator?, a) Python only evaluates the second argument if the first one is False, b) Python only evaluates the second argument if the first one is True, c) Python only evaluates True if any one argument is True, d) Python only evaluates False if any one argument is False, Answer: b, 9. Which of the following forces an expression to be converted into specific type?, a) Implicit type casting, b) Mutable type casting, c) Immutable type casting, d) Explicit type casting, KVSRO ERNAKULAM, , 55
Page 65 :
Answer: d, 10.Which point can be considered as difference between string and list?, a) Length, b) Indexing and Slicing, c) Mutability, d) Accessing individual elements, Answer: c, 11.Which of the following statement is true for extend () list method?, a) adds element at last, b) adds multiple elements at last, c) adds element at specified index, d) adds elements at random index, Answer: b, 12.The statement del l[1:3] do which of the following task?, a) deletes elements 2 to 4 elements from the list, b) deletes 2nd and 3rd element from the list, c) deletes 1st and 3rd element from the list, d) deletes 1st, 2nd and 3rd element from the list, Answer: b, 13. If l=[11,22,33,44], then output of print(len(l)) will be, a) 4, b) 3, c) 8, d) 6, Answer : a, 14. Which of the following method is used to delete element from the list?, a) del(), b) delete(), c) pop(), d) All of these, Answer : c, 15 The step argument in range() function _________., a. indicates the beginning of the sequence, b. indicates the end of the sequence, c. indicates the difference between every two consecutive numbers in the sequence, d. generates numbers up to a specified value, , Answer : c, 16. The statement del L[1:3] do which of the following task?
Page 66 :
57, a) Deletes elements 2 to 4 elements from the list, b) Deletes 2nd and 3rd element from the list, c) Deletes 1st and 3rd element from the list, d) Deletes 1st, 2nd and 3rd element from the list, Answer : b, , MCQ, SECTION B, 1. What will be the output of the following Python code?, if (9 < 0) and (0 < -9):, print("hello"), elif (9 > 0) or False:, print("good"), else:, print("bad"), a) error, b) hello, c) good, d) bad, Answer: c, 2. What will be the output of the following Python code?, x = ['ab', 'cd'], for i in x:, i.upper(), print(x), a) [‘ab’, ‘cd’], b) [‘AB’, ‘CD’], c) [None, None], d) none of the mentioned, Answer: a, Explanation: The function upper() does not modify a string in place, it returns a new string, which isn’t being stored anywhere., 3. What will be the output of the following Python code?, x = ['ab', 'cd'], for i in x:, KVSRO ERNAKULAM, , 57
Page 67 :
x.append (i.upper ()), print(x), a) [‘AB’, ‘CD’], b) [‘ab’, ‘cd’, ‘AB’, ‘CD’], c) [‘ab’, ‘cd’], d) none of the mentioned, Answer: d, Explanation: The loop does not terminate as new elements are being added to the list in, each iteration., , 4. What will be the output of the following Python code?, i=1, while True:, if i%3 == 0:, break, print(i), i+=1, a) 1 2, b) 1 2 3, c) error, d) none of the mentioned, Answer: c, Explanation: SyntaxError, there shouldn’t be a space between + and = in +=., 5. What will be the output of the following Python code?, string = "my name is x", for i in string:, print (i, end=", "), a), b), c), d), , m, y, , n, a, m, e, , i, s, , x,, m, y, , n, a, m, e, , i, s, , x, my, name, is, x,, error, , Answer: a, Explanation: Variable i takes the value of one character at a time., 6. What will be the output of the following Python code?, string = "my name is x", for i in string.split():, print (i, end=", "), a) m, y, , n, a, m, e, , i, s, , x,, b) m, y, , n, a, m, e, , i, s, , x, c) my, name, is, x,
Page 68 :
59, d) error, Answer: c, Explanation: Variable i takes the value of one word at a time., 7. What will be the output of the following Python code snippet?, a = [0, 1, 2, 3], for a[-1] in a:, print(a[-1]), a) 0 1 2 3, b) 0 1 2 2, c) 3 3 3 3, d) error, , Answer: b, Explanation: The value of a[-1] changes in each iteration., 8. Which of this a correct statement?, a) xyz = 10 100 1000, b) x y z = 10 100 1000, c) x, y, z = 10, 100, 1000, d) x y z= 10, 100, 1000, 9. Assume the list superstore is [1,2,3,4,5], which of the following is correct syntax for slicing, operation?, a. print(superstore[0:]), b. print(superstore[:2]), c. print(superstore[:-2]), d. All of these, 10. If zoo = ["lion", "tiger"], what will be zoo * 2?, a. ['lion'], b. ['lion', 'lion', 'tiger', 'tiger'], c. ['lion', 'tiger', 'lion', 'tiger'], d. ['tiger'], 11. To add a new element to a list the statement used is?, a. zoo. add(5), b. zoo.append("snake"), c. zoo.addLast(5), d. zoo.addend(4), 12. What will be the output of the following?, data = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]], print(data[1][0][0]), KVSRO ERNAKULAM, , 59
Page 69 :
a. 1, b. 2, c. 4, d. 5, 13. Consider phone_book = {"Kalpana":7766554433, "Steffi":4499551100}. To delete the key, "Kalpana" the code used is, a. phone_book.delete("Kalpana":7766554433), b. phone_book.delete("Kalpana"), c. del phone_book["Kalpana"], d. del phone_book("Kalpana":7766554433), 14. Assume d = {"Guido":"Python", "Dennis":"C"}. To obtain the number of entries in dictionary the, statement used is, a. d.size(), b. len(d), c. size(d), d. d.len(), 15. What will be the output of the following code snippet?, numbers = {}, letters = {}, comb = {}, numbers[1] = 56, numbers[3] = 7, letters[4] = "B", comb["Numbers"] = numbers, comb["Letters"] = letters, print(comb), a. Nested dictionary cannot occur, b. 'Numbers': {1: 56, 3: 7}, c. {'Numbers': {1: 56}, 'Letters': {4: 'B'}}, d. {'Numbers': {1: 56, 3: 7}, 'Letters': {4: 'B'}}, MCQ, SECTION 3: CASE STUDY, 1. Mr. Rahul wants created a dictionary to store the details of his students and to manipulate the, data. He wrote a code in Python, help him to complete the code:, studentDict = dict() # stmt 1, n = int(input("How Many Students you Want To Input?")), for i in range(___): # stmt 2 - to enter n number of students details, rollno = input("Enter Roll No:"), name = input("Enter Name:"), physicsMarks = int(input("Enter Physics Marks:")), chemistryMarks = int(input("Enter Chemistry Marks:")), mathMarks = int(input("Enter Maths Marks:")), studentDict[rollno]=[name, physicsMarks, chemistryMarks, mathMarks] # stmt 3, , (i) What is the use of stmt 1?
Page 70 :
61, a), b), c), d), , To initialize a dictionary., To declare an empty dictionary., To clear the dictionary, None of the above, Answer: b, , (ii), , Fill in the blank space at stmt 2:, a. 1,0, b. n, c. size(studentDict), d. 10, , (iii), , Write appropriate statement to add data to dictionary, stmt 3., a) studentDict[rollno] = [name, physicsMarks, chemistryMarks, mathMarks], b) studentDict.add (name, physicsMarks, chemistryMarks, mathMarks), c), , 2. Consider the following code and answer the questions that follow:, Book = { 1: ‘Thriller’, 2: ‘Mystery’, 3: ‘Crime’ , 4: ‘Children Stories’ }, Library = {‘5’ : ‘Madras Diaries’, ‘6’ : ‘Malgudi Days’ }, (i), , Bobby needs to change the title in the dictionary book from ‘Crime’ to ‘Crime Thriller’. He, has written the following command:, Book[‘Crime’] = ‘Crime Thriller’, But he is not getting the answer. Help him choose the correct command:, a) Book[2] = ‘Crime Thriller’, b) Book[3] = ‘Crime Thriller’, c) Book[2] = (‘Crime Thriller’), d) Book[3] = (‘Crime Thriller’), Answer: b, , (ii), , The command to merge the dictionary Book with Library the command would be:, a. d=Book + Library, b. print (Book + Library, c. Book.update(Library), d. Library.update(Book), Answer: c, , (iii), , What will be the output of the following line of code:, print ( list ( Library), a) [‘5’, ‘Madras Diaries’, ‘6’, ‘Malgudi Days’], b) (‘5’, ‘Madras Diaries’, ‘6’, ‘Malgudi Days’), KVSRO ERNAKULAM, , 61
Page 71 :
c) [‘Madras Diaries’,’Malgudi Days’], d) [‘5’,’6’], Answer: d, (iv), , In order to check whether the key 2 is present in the dictionary Book, Ramesh uses the, following command:, 2 in Book, He gets the answer as ‘True’. Now to check whether the name ‘Madras Diaries’ exist in the, dictionary Library, he uses the following command:, ‘Madras Diaries’ in Library, But he gets the answer as ‘False’. Select the correct reason for this., a., b., c., d., , We cannot use the in operator with values. It can be used with keys only., We must use the function Library.values() along with the in operator., We can use the Library.items() function instead of the in operator., Both (b) and (c), Answer: a, , MIND MAPPING, , MAKING TRUE, COPY, , MUTABLE, DATATYPE, , •list(), •[], , •copy(), , JOINING LIST, •+(operator), , CREATE, , LIST, , DELETE, •pop(), •remove(), •clear(), •del, , MODIFY, REPEATING, , •append(), •extend(), •insert(), , •* (operator), , ACCESSING, using INDEX
Page 72 :
63, , MUTABLE, DATATYPE, MAKING TRUE, COPY, , CREATE, • dict(), •{ }, , • copy(), , DELETE ITEMS, , DICTIONARY, , • pop(), • popitems(), , DELETE, • del, • clear(), , ACCESSING using, KEY, • get(), • items(), • keys(), • values(), , MODIFY, • append(), • extend(), • insert(), , KVSRO ERNAKULAM, , 63
Page 73 :
65, , FUNCTIONS, A group of statements within a program that perform as specific task., Usually one task of a large program., Functions can be executed in order to perform overall program task, Known as divide and conquer approach, FUNCTION DEFINITION, A function is a named sequence of statement(s) that performs a computation. It contains, line of code(s) that are executed sequentially from top to bottom by Python interpreter., They are the most important building blocks for any software in Python., Functions can be categorized as i., , Built-in functions, , ii., , Functions defined in module, , iii., , User defined functions, , Built-in functions, Built in functions are the function(s) that are built into Python and can be accessed by a, programmer., These are always available and for using them, we don’t have to import any module (file)., , Name, , of the, , Description, , Example, , function, abs (x), , It returns distance between x and zero, >>>abs(-45) 45 >>>abs(119L), where x is a numeric expression., , max( x, y, z, ..... ), , 119, , It returns the largest of its arguments: >>>max(80, 100, 1000) 1000, where, , x,, , y, , and, , z, , are, , numeric >>>max(-80, -20, -10) -10, , variable/expression., min( x, y, z, ..... ), , It returns the smallest of its arguments; >>> min(80, 100, 1000) 80 >>>, where, , x,, , y,, , and, , z, , are, , numeric min(-80, -20, -10) -80, , variable/expression., , KVSRO ERNAKULAM, , 65
Page 74 :
66, , cmp( x, y ), , It returns the sign of the difference of two >>>cmp(80,, , 100), , -1, , numbers: -1 if x < y, 0 if x == y, or 1 if x > y, >>>cmp(180, 100) 1, where, , x, , and, , y, , are, , numeric, , variable/expression., divmod (x,y ), , Returns both quotient and remainder by >>> divmod (14,5) (2,4) >>>, division through a tuple, when x is divided divmod, by y; wherex & y are variable/expression., , len (s), , (2.7,, , 1.5), , (1.0,, , 1.20000), , Return the length (the number of items) of >>> a= [1,2,3] >>>len (a) 3 >>>, an object. The argument may be a sequence b= „Hello‟ >>> len (b) 5, (string, tuple or list) or a, , mapping, , (dictionary)., range, , (start,, , stop[, step]), , This is a versatile function to create lists >>> range(10)- [0, 1, 2, 3, 4, 5,, containing arithmetic progressions. It is 6, 7, 8, 9], most often used, , in for loops. The >>> range(1, 11)- [1,2, 3, 4, 5,, , arguments must be plain integers. If the 6, 7, 8, 9, 10], step argument is omitted, it defaults to, , >>>range(0, 30, 5)- [0, 5, 10,, , 1. If the start argument is omitted, it 15,20, 25], defaults to 0. The full form returns a list of >>> range(0, 10, 3)- [0,, plain integers [start, start + step, start + 2 * 3, 6, 9], step, ...]. If step is positive, the last element >>> range(0, -10, -1)- [0,, is the largest start + i * step less than stop; if -1, -2, -3, -4, -5, -6, -7, -8, -9], step is negative, the last element is the >>> range(0) - [], smallest start + i * step greater than stop., , >>> range(1, 0) - [], , step must not be zero (or else Value Error is, raised)., round( x [, n] ), , It returns float x rounded to n digits from the >>>round(80.23456, 2) 80.23, decimal point, where x and n are numeric >>>round(-100.000056, 3) expressions. If n is not provided then x is, rounded to0 decimal digits., , 100.0, >>> round (80.23456), KVSRO ERNAKULAM, , 66
Page 75 :
67, , 80.0, , ii., , Functions defined in module, , A module is a file containing Python definitions (i.e., functions) and statements., Standard library of Python is extended as module(s) to a programmer. Definitions from the, module can be used within the code of a program. To use these modules in the program, a, programmer needs to import the module., How to import a module, There are many ways to import a module in your program, the one's which you should, know are:, Import, From, Import, It is simplest and most common way to use modules in our code., Its syntax is:, import modulename1 [,modulename2, ---------], Example, >>> import math, To use/ access/invoke a function, you will specify the module name and name of the functionseparated by dot (.). This format is also known as dot notation., Example, >>> value= math. sqrt (25) # dot notation, , From Statement, It is used to get a specific function in the code instead of the complete module file. If we know, beforehand which function(s), we will be needing, then we may use from. For modules having, large no. of functions, it is recommended to use from instead of import., Its syntax is:, KVSRO ERNAKULAM, , 67
Page 76 :
68, , >>> from modulename import functionname [, functionname…..], >>>from modulename import * ( Import everything from the file), Example, >>> from math import sqrt, value = sqrt (25), Some functions from math module are :, Name of, , Description, , Example, , the, function, ceil( x ), , It returns the smallest integer not less math.ceil(-45.17), , -45.0, , than x, where x is a numeric expression., , 101.0, , math.ceil(100.12), , math.ceil(100.72) 101.0, floor( x ), , It returns the largest integer not greater math.floor(-45.17), , -46.0, , than x, where x is a numeric expression., , 100.0, , math.floor(100.12), , math.floor(100.72) 100.0, fabs( x ), , It returns the absolute value of x, where x math.fabs(-45.17), is a numeric value., , math.fabs(100.12), , 45.17, 100.12, , math.fabs(100.72) 100.72, exp( x ), , It returns exponential of x: e x, where x is math.exp(-45.17), a numeric expression., , 2.41500621326e-20, math.exp(100.12), 3.03084361407e+43, math.exp(100.72), 5.52255713025e+43, , log( x ), , It returns natural logarithm of x, for x > 0, math.log(100.12), where x is a numeric expression., , 4.60636946656, math.log(100.72), , KVSRO ERNAKULAM, , 68
Page 77 :
69, , 4.61234438974, , log10( x ), , It returns base-10 logarithm of x for x > 0, math.log10(100.12), where x is a numeric expression., , 2.00052084094, math.log10(100.72), 2.0031157171, , pow( x, y ), , It returns the value of xy, where x and y math.pow(100, 2) 10000.0, are numericexpressions., , math.pow(100, -2), 0.0001 math.pow(2, 4) 16.0, math.pow(3, 0) 1.0, , sqrt (x ), , It returns the square root of x for x > 0, math.sqrt(100) -10.0, where x is a numeric expression., , math.sqrt(7)2.6457513110645907, , cos (x), , It returns the cosine of x in radians, where x math.cos(3) -0.9899924966, is anumeric expression, , math.cos(-3)-0.9899924966, math.cos(0) 1.0, math.cos(math.pi) -1.0, , sin (x), , It returns the sine of x, in radians, where x math.sin(3) 0.14112000806, must be anumeric value., , math.sin(-3), , -, , 0.14112000806, math.sin(0)-0.0, tan (x), , It returns the tangent of x in radians, where math.tan(3), x must bea numeric value., , -, , 0.142546543074, math.tan(-3), 0.142546543074, math.tan(0) 0.0, , KVSRO ERNAKULAM, , 69
Page 78 :
70, , degrees (x), , It converts angle x from radians to math.degrees(3), degrees, wherex must be a numeric value., , 171.887338539, math.degrees(-3)171.887338539, math.degrees(0) 0.0, , radians(x), , It converts angle x from degrees to radians, math.radians(3), wherex must be a numeric value., , 0.0523598775598, math.radians(-3), 0.0523598775598, math.radians(0)- 0.0, , Some functions from random module are :, Name of the function, , Description, , random ( ), , It returns a random float x, >>random.random(, such that 0 ≤ x, , Example, ), , 0.281954791393, >>>random.random(, , ), , 0.309090465205, randint (a, b), , It returns a int x between a >>> random.randint (1,10) 5, & b such that a ≤ x ≤ b, , >>> random.randint (2,20), -1, , uniform (a,b), , It returns a floating point, , >>>random.uniform (5, 10), , number x, such that a <= x 5.52615217015, <b, randrange ([start,] stop It returns a random item >>>random.randrange(100,1, [,step]), , from the given range, , 000,3) 150, , Some functions from statistics module are :, Name of the function, , Description, , Example, , KVSRO ERNAKULAM, , 70
Page 79 :
71, , mean(x), , It returns arithmetic mean, , >>>statistics.mean([11,24,32,, 45,51]) 32.6, , median(x), , It returns median (middle >>>statistics., value) of x, , mode(x), , median([11,24,32,45,51]) 32, , It returns mode (the most >>>statistics.mode([11,24,11, repeated value), , ,45,11]) -11, >>>statistics.mode(("red","bl, ue","red"))'red', , Some of the other modules, which you can explore, are: string, time, date., iii., , User defined functions, ❖ To define a function keyword def is used, ❖ After the keyword comes an identifier i.e. name of the function, followed by parenthesized list, of parameters and the colon which ends up the line., ❖ Next follows the block of statement(s) that are the part of function., , Creating User Defined Function, Syntax to define a user defined function:, def <function_name> ( [ parameters] ): # def is a keyword, statement1 # parameters are optional, statement2 # function name is an identifier, ----------------------------------return <value> # here return is a keyword, Example:, def area_of_circle( radius ):, print(“Area of circle = “, 3.1416*radius*radius), r=int(input(“Enter radius of circle”)), area_of_circle(r), output:, Enter radius of circle 10, KVSRO ERNAKULAM, , 71
Page 80 :
72, , Area of circle = 314.16, , Points about User Defined Functions:, ➢ Every User Defined Function start with the Keyword def., ➢ The first line of the function is called Function Definition., ➢ Function name must follow norms of valid identifier., ➢ Every function header end with parenthesis and colon sign followed by function name, ➢ We can provide parameters inside parenthesis, which is optional., ➢ The return statement is used to return a value from function. The return statement is, also optional. The function should return a value only at the place from where it get’s, called., ➢ To use a function, it must be called or invoked in main program., Type of user defined functions:, The user defined functions can be categorized in following 4 categories:, 1.Function which accept arguments and return some value, 2.Function which accept arguments but return no value, 3.Functions which do not accept any argument but return some value, 4.Functions which do not accept any argument and even not return any value, , Parameters/Arguments passed to functions: These are the values passed to user defined, functions from the calling function. If you are passing values of immutable types (i.e., numbers,, strings,etc) to the Called function, then the called function cannot alter their values., ➢ If you are passing values of mutable types (i.e., List, Dictionary, etc.) to the Called, function, then the called function can make changes to them., They are categorized in following two types:, ➢ Formal Parameters or Formal Arguments: These are the values provided in Parenthesis, when we write a function Header., ➢ Actual Parameters or Actual Arguments: These are the values passed to the function, when it is called/invoked., KVSRO ERNAKULAM, , 72
Page 81 :
73, , Example:, def area_of_circle( radius ): # here radius is the Formal Parameter or Formal Argument, print(“Area of circle = “,3.1416*radius*radius), r=int(input(“Enter radius of circle”)), ar=area_of_circle(r) # here r is the Actual Parameter or Actual Argument, output:, Enter radius of circle 10, Area of circle = 314.16, Types of Arguments:, In Python following four types of arguments allowed:, ❖ Positional Arguments, ❖ Default Arguments, ❖ Keyword Arguments, ❖ Variable length Arguments, , Functions: types of function (built-in functions, functions defined in module, user defined, functions), creating user defined function, arguments and parameters, default, parameters, positional parameters, function returning value(s), flow of execution,, scope of a variable (global scope, local scope), , (i) Default Parameters, The parameters which are assigned with a value in function header while defining the, function are known as default parameters. This value is optional for the parameter. If a, user explicitly passes the value in function call, then the value which is passed by the, user will be taken by the default parameter. If no value is provided, then the default, value will be taken by the parameter. Default parameters will be written in the end of the, function header, means positional parameter cannot appear to the right side of, default parameter., KVSRO ERNAKULAM, , 73
Page 82 :
74, , Example:, def SICal(amount, rate, time=10):, , #Function definition header, , (ii) Required Arguments /Positional Parameters, When the function call statement must match the number and positional order of, arguments as defined in the function definition, this is called the positional parameters., , Example:, def Test(x,y,z): #function definition header, , Then we can call function using following statements, p,q,r=3,4,6, Test(p,q,r), , #3 variables are passed, , Test(4,q,r), , # 1 literal and 2 variables are passed, , Test(5,6,7), , # 3 literals are passed., , So x,y,z are positional parameters and the value must be provided to these parameters, , (iii) Keyword arguments:, Keyword arguments are related to the function calls. When you use keyword arguments, in a function call, the caller identifies the arguments by the parameter name. This allows, you to place argument out of order because the Python interpreter is able to use the, keywords provided to match the values with parameters., def show(x,y):, print(“Name is “,x), print(“Age is “,y), show(y=18,x=”Raj”), ., OUTPUT, Name is Raj, Age is 18, KVSRO ERNAKULAM, , 74
Page 83 :
75, , (iv) Variable Number of Arguments:, In cases where you don’t know the exact number of arguments that you want to pass to, a function, you can use the following syntax with *args: The variable stored in *args are, represented in the form of tuple., def change(*a):, for i in a:, print(i), print(a), change(10,5), change(15,20,25), OUTPUT, 10, 5, (10, 5), 15, 20, 25, (15, 20, 25), , (v) Arguments are passed as a dictionary (**kwargs):, Kwargs allow you to pass keyword arguments to a function. They are used when you, are not sure of the number of keyword arguments that will be passed in the function., Kwargs can be used for unpacking dictionary key, value pairs. This is done using the, double asterisk notation ( ** )., In the function, we use the double asterisk ** before the parameter name to denote this, type of argument. The arguments are passed as a dictionary and these arguments, make a dictionary inside function with name same as the parameter excluding double, asterisk **, Example:, def fun(**data):, KVSRO ERNAKULAM, , 75
Page 84 :
76, , print(“\nData type of argument:”,type(data)), print(data), for key, value in data.items():, print(key,value), fun(Name=”Aman”,Age=18,Marks=56), OUTPUT, Data type of argument: <class ‘dict’>, {‘Name’: ‘Aman’, ‘Age’: 18, ‘Marks’: 56}, Name Aman, Age 18, Marks 5, •, , A function can return multiple values. The return values should be a commaseparated list of values and Python then constructs a tuple and returnsthis to, the caller., , •, , Having a positional argument after keyword areguments will result into error, , •, , What is the difference between parameter and argument?, Ans. Parameters are temporary variable names within functions. The argument can, be thought of as the value that is assigned to that temporary variable. For instance,, lets consider the following simple function to calculate sum of two numbers., def sum(a,b):, return a+b, sum(10,20), a,b here are the parameter for the function ‘sum’., Arguments are used in procedure calls, i.e. the values passed to the function at runtime.10,20 are the arguments for the function sum, , SCOPE OF VARIABLES:, Scope of a variable is the portion of a program where the variable is recognized and can, be accessed therein., , KVSRO ERNAKULAM, , 76
Page 85 :
77, , There are two types of scope for variables:, 1. Local Scope, 2. Global Scope, , 1.Local Scope:, A variable declared in a function-body is said to have local scope.It can not be accessed, outside the function. In this scope, the lifetime of variables inside a function is as long as, the function executes., , 2. Global Scope:, A variable declared in top level segment (__main__) of a program is said to have a, global scope., In this scope, lifetime of a variable inside a program is as long as the program executes., Example 1:, def Sum(x , y) :, z=x+y, return z, a=5, b=7, s = Sum(a , b), print(s), In the above program x, y and z are local variables and are destroyed once we return, from the function. a, b and s are global variables and remains in the memory until the, program executes., , Example 2:, def my_func( ):, x=10, , # local variable, , print(“Value inside function:”,x), x=20, , # global variable, , my_func( ), KVSRO ERNAKULAM, , 77
Page 86 :
78, , print(“Value outside function:”,x), , Output:, Value inside function:10, Value outside function:20, , Here, we can see that the value of x is 20 initially. Even though the function my_func(), changed t he value of x to 10, it did not affect the value outside the function. This is, because the variable x inside the function is different (local to the function) from the one, outside. Although they have same names, they are two different variables with different, scope. On the other hand, variables outside of the function are visible from inside. They, have a global scope., , RANDOM FUNCTION, •, , randint(), randint(x,y) will return a value>=x and <=y. It will generate a random number, from the inclusive range., eg: random.randin(0,50) will return a random number between 0 and 50, (both inclusive), , •, , randrange(), randrange(x,y) will return a value>=x and <y. The randrange(start, stop, step), doesnot include the stop number while generating random integer.ie. stop is, exclusive., eg. random.randrange(0,50) will return a random number between 0 and, 49., , SECTION A, 1, , Which of the following is a valid function name?, a)Start_game(), , 2, , b) start game() c) start-game(), , d) All of the above, , . If the return statement is not used in the function then which type of value will be, returned by the function?, KVSRO ERNAKULAM, , 78
Page 87 :
79, , a), 3, , int, , b) str, , c) float, , d) None, , Richa is working with a program where she gave some values to the function. She, doesn’t know the term to relate these values. Help her by selecting the correct option., , 4, , a) function value, , b) arguments or parameters, , c) return values, , d) function call, , What is the minimum and maximum value of c in the following code snippet?, import random, a = random.randint(3,5), b = random.randint(2,3), c=a+b, print(c), a) 3 , 5, , 5, , b) 5, 8, , c) 2, 3, , d) 3, 3, , In python function, the function calling another function is known as ______and the, function being called is known ___________, , 6, , a) main, keyword, , b) caller, called, , c) called, caller, , d) executer, execute, , What will be the output of the following code ?, print(“100+200”), a) 300, , 7, , b) 100200, , d) 200, , pow( ) function belongs to which library ?, a) math, , 8, , c) 100+200, , b) string, , c) random, , d) maths, , What data type is the object below?, L = (1, 23, ‘hello’,1), a) list, , 9, , b) 9, , d) tuple, , c) error, third argument required d) error, too many arguments, , Which of the following is not a type conversion functions?, a) Int(), , 11, , c) array, , What is returned by int(math.pow(3, 2))?, a) 6, , 10, , b) dictionary, , b) Str(), , c) Input(), , d) Float(), , Write the output of the following:, print(float()), , KVSRO ERNAKULAM, , 79
Page 88 :
80, , a) 1.0, 12, , b) 0.0, , d) zero, , Identify the module to which the following function load ( ) belong to?, a) math, , 13, , c) Any floating-point number, , b)random c)pickle d) sys, , How many argument(s) a function can receive, a) Only one b) 0 or many c) Only more than one d) At least one, , 14, , Give the output, def fun():, global a, a=10, print(a), a=5, fun(), print(a), , 15, , a) 10, , b) 5, , c) 5, , 10, , 10, , 5, , b) False, , The variable declared inside the function is called a ___________ variable, a) global, , 17, , 5, , Value returning functions should be generally called from inside of an expression, a) True, , 16, , d) 10, , b) local, , c) external, , d) none of the above, , These are predefined functions that are always available for use. For using them we, don’t need to import any module, , 18, , a) built in function, , b) pre define function, , c) user defined function, , d) none of the above, , The _________ of a variable is the area of the program where it may be referenced, a) external, , 19, , b) global, , c) scope, , d) local, , If you want to communicate between functions ie. calling and called statement, then, you should use __________, a) values, , 20, , b) return c)arguments, , d) none of the above, , Which of the following function header is correct, a) def mul(a=2, b=5,c), , b) def mul(a=2, b, c=5), , KVSRO ERNAKULAM, , 80
Page 89 :
81, , c) def mul(a, b=2, c=5), 21, , b) def mul(a=2, b, c=5), , Find the flow of execution of the following code :, 1., , def calculate (a, b):, , 2., , res=a**b, , 3., , return res, , 4., 5., , def study(a):, , 6., , ans=calculate(a,b), , 7., , return ans, , 8., 9., , n=2, , 10., , a=study(n), , 11., , print(a), a) 1 > 5 > 9 > 10 >6 > 2 > 3 > 7 > 11, , b) 5 > 9 > 10 > 6 > 2 > 3 > 7 > 11, , c) 9 > 10 > 5 > 1 > 6 > 2 > 3 > 7 > 11, 22., , Python resolves the scope of a name using the LEGB rule, a) True, , 23, , b) False, , A void function internally returns legal empty value __________, a) None, , 24, , d) None of the above, , b) Close(), , c) Return, , d) all, , When you use multiple type argument in function, then default argument take place, _________, a) at beginning b) at end, , 25, , Ans, , c) anywhere, , d) none of the above, , A ________ can be skipped in the function call statements, a) named parameter, , b) default parameter, , c) keyword parameters, , d) all of the above, , 13. b) 0 or many, 14. a), , 10, 10, , 15. a) True, , KVSRO ERNAKULAM, , 81
Page 90 :
82, , 16. b) local, 17. a) built in function, 18. c) scope, 19. c) arguments, 20. c) def mul(a, b=2, c=5), 21. a) 1 > 5 > 9 > 10 >6 > 2 > 3 > 7 > 11, 22. a) True, 23. a) None, 24. b) at end, 25. b) default parameter, , SECTION B, 1. What will be the output of the following Python code?, def cube(x):, return x * x * x, x = cube(3), print x, a), , 9, , b)3, , c)27, , d) 30, , 2. Which of the following items are present in the function header?, a) function name, b) parameter list, c) return value, d) Both A and B, , 3. What is the output of the following snippet?, def fun (n):, if (n > 100):, return n - 5, return fun (fun, (n+11)), KVSRO ERNAKULAM, , 82
Page 91 :
83, , print (fun (45)), , a) 50, , b) 100, , c)74, , d) Infinite loop, , 4. Predict the output of the following code, def func1(list1):, for x in list1:, print(x.lower(),end=”#”), func1([‘New’,’Dehli’), , A. [New,Dehli], B. new#dehli#, C. newdehli#, D. New#Dehli#, , 5. What will be the output of the following python code:, def mul (num1, num2):, x = num1 * num2, x = mul(20,30), A. 600, , B. None, , C. No Output, , D. 0, , 6.Which of the following function header is Correct :, A. def fun(x=1,y), B. def fun(x=1,y,z=2), C. def fun(x=1,y=1,z=2), D. def fun(x=1,y=1,z=2,w), , 7. What is the output of the program given below?, x = 50, def func (x) :, x=2, KVSRO ERNAKULAM, , 83
Page 92 :
84, , func (x), print ('x is now', x), , A) x is now 50, , B) x is now 2, , C) x is now 100, , D) Error, , 8. Choose the correct output from the options given below., print(‘Welcome!’), print(‘Iam’,__name__) # __ is double underscore, , a), , b), a) d) None of the above, , c), Answer a), , 9. Find the output, , a), , b), , KVSRO ERNAKULAM, , 84
Page 93 :
85, , c), , d) None of the above, , Answer c), , 10. Predict the output of the following code fragment., , b), , a), , d) None of the above, , c), Answer b), 11. Find the output, print(pow(5,4,9)), a)7, , 12, , b)0, , c)4, , d)error, , Give the output of the following program, def check(a):, for i in range(len(a)):, a[i]=a[i]+5, return a, b=[1,2,3,4], KVSRO ERNAKULAM, , 85
Page 94 :
86, , c=check(b), print(c), , a) [6, 8, 8, 9], , b) [6, 7, 8, 9], , c) [7, 7, 8, 9], , d) [6, 7, 9, 9], , Ans. b), 13, , [6, 7, 8, 9], , Give the output, def abc(x,y=60):, return x+y, a=20, b=30, a=abc(a,b), print(a,b), b=abc(a), print(a,b), a=abc(b), print(a,b), , a) 50 30 50 110 170, , b) 30 50 110 170 110, , c) 50 30, , d) 50 30 50 110 170 110, , 50 110, 170 110, , Ans., , c) 50 30, 50 110, 170 110, , 14, , def Execute(M):, if M%3= =0:, return M*3, else:, KVSRO ERNAKULAM, , 86
Page 95 :
87, , return M+10;, , def Output(B=2):, for T in range (0,B):, print(Execute(T),”*”,end=””), print(), , Output(4), Output(), Output(3), , Ans., 0 *11 *12 *9 *, 0 *11 *, 0 *11 *12 *, 15, , Find the output of the following program :, def ChangeIt(Text,C):, T="", for K in range(len(Text)):, if Text[K]>='F' and Text[K]<='L':, T=T+Text[K].lower();, elif Text[K]=='E' or Text[K]=='e':, T=T+C;, elif K%2==0:, T=T+Text[K].upper(), else:, T=T+T[K-1], print(T), , OldText="pOwERALone", ChangeIt(OldText,"%"), KVSRO ERNAKULAM, , 87
Page 97 :
89, , a) 12, , b) 12, , 12, , c) 0, , 0, , d) None, , 12, , Ans : a), 18, , Find the output of the following codes, import random, print(int(15+random.random()*5),end=' '), print(int(15+random.random()*5),end=' '), print(int(15+random.random()*5),end=' '), print(int(15+random.random()*5)), , a) 19 15 16 19, , b) 19 20 16 19, , c) 20 14 16 19, , d) 19 19 19 19, , Ans : (a) and (d), 19, , Choose correct answer, def fun1(num):, return num+5, print(fun1(5)), print(num), , a) Print value 10, , b) Print value 5, , c) Name Error, , d) 25, , Ans c), 20, , Choose the correct option:, Statement1: Local Variables are accessible only within a function or block in which it, is declared., Statement2: Global variables are accessible in the whole program., a. Statement1 is correct but Statement2 is incorrect, b. Statement2 is correct but Statement1 is incorrect, c. Both Statements are Correct, d. Both Statements are incorrect, Ans : c), , 21, , Consider the following code and choose correct answer:, KVSRO ERNAKULAM, , 89
Page 98 : 90, , def nameage(name, age):, return [age,name], t=nameage('kishan',20), print(type(t)), a) tuple, , b) list, , c) (kishan,20), , d) None of all, , Ans : b), 22, , Consider the code given below and Identify how many times the message “Hello, All” will be printed, def prog(name):, for x in name:, if x.isalpha():, print('Alphabet'), elif x.isdigit():, print('Digit'), elif x.isupper():, print('Capital Letter'), else:, print('Hello All'), prog('
[email protected]'), a) 0, , b) 2, , c) 1, , d) 3, , Ans: b), 23, , Write the output of the following:, a=(10, 12, 13, 12, 13, 14, 15), print(max(a) + min(a) + a.count(2)), a) 13, , b) 25, , c) 26, , d) Error, , Ans : b), 24, , What will be the output for the below code snippet:, def div(lst,n):, for i in range(0,n):, if lst[i]%5==0:, KVSRO ERNAKULAM, , 90
Page 99 :
91, , lst[i]+=5, else:, lst[i]=lst[i]//2, lt=[45,20,23,54,5], div(lt, len(lt)), for i in lt:, print(i,end='#'), , a) 50#25#11.5#27.0#10#, , b) 50#25#11#27#10#, , c) 50#25#1#0#10#, , d) 225#100#1#0#25#, , Ans : b), 25, , What will be the correct output for the following code after removing the syntactical, error. Mention the identified error., def check(x=4, y):, if x != y:, return x+5, else:, return y+10, print(check(10,5)), a) 15, b) 20, , c) 5, , d) 10, , Ans. a), , SECTION C, fig 1, , Based on the code (fig 1) given above answer following questions., KVSRO ERNAKULAM, , 91
Page 100 :
92, , 1. Give the output of LINE 1, a) list within called function after all changes [3,5,6], b) list within called function after all changes[1,4,6], c) list before function call [1,4,3,5,6], d) error, , 2. Give the output of LINE 2, a. list before function call [1,4,6], b. list before function call [1,4], c. list before function call [3,5,6], d. Value Error, , 3. Give the output of LINE 3, a) list after function call [3,5,6], b) list after function call [1,4], c) list after function call [1,4,6], d) Value Error, , KVSRO ERNAKULAM, , 92
Page 102 :
94, DATA FILE HANDLING, , File- A file is a sequence of bytes on the disk/permanent storage where a group of related data, is stored. File handling in Python enables us to create, update, read, and delete the files stored, on the file system through our python program., Data File handling takes place in the following order., 1- Opening a file., 2- Performing operations (read, write) or processing data., 3- Closing the file., Types of File in Python:, Python allows us to create and manage three types of data files., 1- Text file, 2- Binary file, 3- CSV file, , Text file: A text file is simply a sequence of ASCII or Unicode characters.A line is a sequence of, characters, stored on permanent storage. In a text file, each line is terminated by a special, character, known as End Of Line (EOL). Text file can be created using any text editor. Ex., Myfile.txt., Binary file: A binary file stores the data in the same way as stored in the memory. The .exe files,, mp3 file, image files, word documents are some of the examples of binary files. We can’t read a, binary file using a text editor., CSV file: CSV (Comma Separated Values) is a file format for data storage which looks like a text, file. The information is organized with one record on each line and each field is separated by, comma., Compare text files, binary files and csv files, Sl.no Text file, 1, It is capable to handle, textual data., 2, It consists of series of, lines of a set of letters,, numbers or symbols, (String), , Binary file, It is capable to handle large, file., It consists of data with a, specific pattern without any, delimiter., , CSV file, It is very common format, and platform independent., It consists of plain text with, a list of data with a delimiter., , KVSRO ERNAKULAM, , 94
Page 103 :
95, 3, , 4, , Any text editors like No specific programs can be, notepad can be used to used to read them, python, read them., provides functions to read, data., Every line ends with EOL. There is no specific EOL, character., , It can be read using text, editors like notepads and, spreadsheet software., It, terminates, a, line, automatically when the, delimiter is not used after, data., , Absolute Path – It is a full path of the file from the root directory. Absolute paths ensure that, Python can find the exact file on your computer., Ex : - C:\Users\Tanmay\Desktop\Delete\file_handling.txt, Relative Path – It is the path of the file from the current working directory., Relative Path is the hierarchical path that locates a file or folder on a file system starting from the, current directory. The relative path is different from the absolute path, which locates the file or, folder starting from the root of the file system., Ex., /home/users/c/computerhope/public_html/cgi-bin- Absolute path, ./public_html/cgi-bin – Relative path, Operation On Files In Python, 1.Opening a file– open() function, 2.Read/Write file–, – Read Functions – read() , readline(), readlines(), – Write Functions – write() , writelines(), 3.Close the File – close() Function, 4.Remove the file – remove() Function of OS Module, Read The Contents Of An Existing File, 1.Open the file–, file_object = open(“read_sample.txt”, ’r’) # Relative Path, file_object = open(“C:\Desktop\Notes\sample.txt”) #Absolute Path, 2.Reading the file–, rf = file_object.read(), KVSRO ERNAKULAM, , 95
Page 104 :
96, print(rf), 3.Closing the file–, file_object.close(), , Working of open() function, We use open () function in Python to open a file in read or write mode. open ( ) will return a file, object. To return a file object we use open() function along with two arguments, that accepts file, name and the mode, whether to read or write. So, the syntax being: open(filename, mode). There, are three kinds of mode, that Python provides and how files can be opened:, “ r “, for reading., “ w “, for writing., “ a “, for appending., Modes Description, 1. r, Opens a file for reading only. The file pointer is placed at the beginning of, the file. This is the default mode. Gives error if file does not exist., 2. r+, Opens a file for both reading and writing. The file pointer placed at the, beginning of the file., 3. W, Opens a file for writing only. Overwrites the file if the file exists. If the file, does not exist, creates a new file for writing., 4. w+, Opens a file for both writing and reading. Overwrites the existing file if the, file exists. If the file does not exist, creates a new file for reading and writing., 5. A, Opens a file for appending. The file pointer is at the end of the file if the, file exists. That is, the file is in the append mode. If the file does not exist, it creates a new, file for writing., 6. a+, Opens a file for both appending and reading. The file pointer is at the end, of the file if the file exists. The file opens in the append mode. If the file does not exist, it, creates a new file for reading and writing., Opening a file using with clause, In Python, we can also open a file using with clause., , KVSRO ERNAKULAM, , 96
Page 105 :
97, The syntax of with clause is:, with open (file_name, access_mode) as file_object:, The advantage of using with clause is that any file that is opened using this clause is closed, automatically, once the control comes outside the with clause. In case the user forgets to, close the file explicitly or if an exception occurs, the file is closed automatically. Also, it, provides a simpler syntax., with open(“myfile.txt”,”r+”) as myObject:, content = myObject.read(), Here, we don’t have to close the file explicitly using close() statement. Python will, automatically close the file., Reading from a file, There are three ways to read data from a text file., read() : Returns the read bytes in form of a string. Reads n bytes, if no n specified, reads the, entire file., File_object.read([n]), readline() : Reads a line of the file and returns in form of a string. For specified n, reads at, most n bytes. However, does not reads more than one line, even if n exceeds the length of, the line., File_object.readline([n]), readlines() : Reads all the lines and return them as each line a string element in a list., File_object.readlines(), Note: ‘\n’ is treated as a special character of two bytes., Writing onto text files:, write() function, The write() function will write the content in the file without adding any extra characters., file_name.write(content), writelines() function, , KVSRO ERNAKULAM, , 97
Page 106 :
98, This function writes the content of a list to a file., file_name.writelines(list_of_lines), # Program to show various ways to read data from a file., # Creating a file, file1 = open("myfile.txt", "w"), L = ["This is Delhi \n", "This is Paris \n", "This is London \n"], # Writing data to a file, file1.write("Hello \n"), file1.writelines(L), file1.close() # to change file access modes, file1 = open("myfile.txt", "r+"), print("Output of Read function is "), print(file1.read()), print(), # seek(n) takes the file handle to the nth, # bite from the beginning., file1.seek(0), print("Output of Readline function is "), print(file1.readline()), print(), file1.seek(0), # To show difference between read and readline, print("Output of Read(9) function is "), print(file1.read(9)), print(), file1.seek(0), print("Output of Readline(9) function is "), print(file1.readline(9)), print(), file1.seek(0), , KVSRO ERNAKULAM, , 98
Page 107 :
99, # readlines function, print("Output of Readlines function is "), print(file1.readlines()), print(), file1.close(), Output:, Output of Read function is, Hello, This is Delhi, This is Paris, This is London, , Output of Readline function is, Hello, , Output of Read(9) function is, Hello, Th, , Output of Readline(9) function is, Hello, , Output of Readlines function is, ['Hello \n', 'This is Delhi \n', 'This is Paris \n', 'This is London \n'], , Setting Offsets in a File, if we want to access data in a random fashion, then Python gives us seek() and tell() functions, to do so, KVSRO ERNAKULAM, , 99
Page 108 :
100, , The tell() method, This function returns an integer that specifies the current position of the file object in the file., The position so specified is the byte position from the beginning of the file till the current, position of the file object. The syntax of using tell() is:, file_object.tell(), , The seek() method, This method is used to position the file object at a particular position in a file. The syntax of, seek() is:, file_object.seek(offset [, reference_point]), In the above syntax, offset is the number of bytes by which the file object is to be moved., reference_point indicates the starting position of the file object. That is, with reference to, which position, the offset has to be counted. It can have any of the following values:, 0 - beginning of the file, 1 - current position of the file, 2 - end of file, By default, the value of reference_point is 0, i.e. the offset is counted from the beginning of, the file., For example, the statement fileObject.seek(5,0) will position the file object at 5th byte, position from the beginning of the file., MCQ ON DATA FILE HANDLING, 1., , Which statement will read 5 characters from a file(file object ‘f’)?, a. f.read(), b. f.read(5), c. f.reads(5), d. None of the above, Correct Answer: b, , KVSRO ERNAKULAM 100
Page 109 :
101, 2, , Default EOL character in Python, a. ‘\n’, b. ‘\r’, c. ‘’, d. ‘\t’, Correct Answer: a, , 3, , Which of the following is not a file extension for text files?, a. .txt, b. .ini, c. .rtf, d. .DAT, Correct Answer: d, , 4, , What is a file object?, a. It serves as a link to the file., b. It is a file present in a computer., c. A keyword, d. A module in python, Correct Answer: a, , 5, , Which of the following command is used to open a file “c:\temp.txt” in read-mode only?, a .infile = open(“c:\temp.txt”, “r”), b. infile = open(“c:\\temp.txt”, “r”), c. infile = open(file = “c:\temp.txt”, “r+”), d. infile = open(file = “c:\\temp.txt”, “r+”), Correct answer:b, , 6, , Which of the following command is used to open a file “c:\temp.txt” in write-mode only?, a. outfile = open(“c:\\temp.txt”, “rw”), b.outfile = open(“c:\temp.txt”, “w+”), c.outfile = open(“c:\\temp.txt”, “w”), d.outfile = open(“c:\\temp.txt”, “a”), Correct answer:c, , 7., , What does the <readlines()> method returns?, a.str, b.a list of lines, KVSRO ERNAKULAM 101
Page 110 :
102, c.list of single characters, d.list of integers, Correct answer:b, , 8., , What is the last action that must be performed on a file?, a.save, b.close, c.end, d.write, Correct answer:b, , 9., , A file object is also known as, a.File handle, b.File copy, c.File directory, d.File link, Correct answer:a, , 10. How to open a text file in write and read mode?, a. r+, b. a+, c. wr, d. wb, Correct answer:a, , 11. Syntax for closing a file:, a. closefile(<file object>), b. <fileobject>.close(), c. <filename>.closer(), d. closefile.<fileobject>, Correct answer:b, 12. Which method can not be used to read from files?, a. read(), b. readlines(), c. readlines(<filename>), d. readline(), KVSRO ERNAKULAM 102
Page 111 :
103, Correct answer:c, 13. What does strip() function do?, , a. Removes the trailing or leading spaces, if any., b. Deletes the file, c. Remove the file object, d. Removes all the spaces between words, , Correct answer:a, 14. When reading a file using the file object, what method is best for reading the entire file into a, single string?, a. readline(), b. read_file_to_str(), c. read(), d. readlines(), Correct answer:c, 15. Which file can open in any text editor and is in human readable form?, a. Binary files, b. Text files, c. Data files, d. Video files, Correct answer:b, 16. Which function breaks the link of file-object and the file on the disk?, a. close(), b. open(), c. tell(), d. readline(), Correct answer:a, , 17. Which function reads the leading and trailing spaces along with trailing newline character, ('\n') also while reading the line?, a. readlines(), b. readline(), c. read(), d. flush(), Correct answer:b, 18. Which mode is used to retain its previous data and allowing to add new data?, a. write mode, b. read mode, c. open mode, d. append mode, KVSRO ERNAKULAM 103
Page 112 :
104, Correct answer:d, , 19. Which function forces the writing of data on disc still pending in output buffer?, a. seek(), b. tell(), c. flush(), d. write(), Correct answer:c, 20. Syntax for flush() function is:, a.<fileOobject>(flush()), b.flush().<fileobject>, c.<fileObject>.flush(), d.flush().<file-object>, , Correct answer:c, , 21, , Which function returns the entire file content in a list where each line is one item of the list?, a. readlines(), b. readline(), c. output(), d. Input(), , Correct answer:a, 22, , Which function is used to remove the given character from trailing end i.e. right end?, a. strip(), b. remove(), c. Istrip(), d. rstrip(), , Correct answer:d, 23, , Sometimes the last lap of data remains in buffer and is not pushed onto disk until a, operation is performed., a. dump(), b. close(), c. load(), d. open(), Correct answer:b, , 24. The position of a file-pointer is governed by the, a. File mode, b. append mode, c. write mode, d. open mode, Correct answer:a, , ., , KVSRO ERNAKULAM 104
Page 113 :
105, 25. In which mode the file must exist already, otherwise python raises an error?, a. read mode, b. write mode, c. binary mode, d. None of these, , Correct answer:a, 26. What is the prefix r stands for in file path?, a. raw string, b. read, c. write, d. append, Correct answer:a, 27. In which mode, a. read write mode, b. read mode, c. write mode, d. All of these, Correct answer:c, , if the file does not exist, then the file is created?, , 28. Which option is correct about this program?, f=open(“ss.txt”,”wb”), print(“Name of the file:”,f.name), f.flush(), f.close(), a. Compilation error, b. Runtime error, c. No output, d. Flushes the file when closing them, Correct answer:d, , 29. What is the output of the following?, import sys sys.stdout.write(‘Hello\n’), sys.stdout.write(‘Python\n’), a. error, b. Runtime error, c. Hello Python, d. Hello, Python, Correct answer:d, , KVSRO ERNAKULAM 105
Page 114 :
106, 30, , Which function is used to read all the characters in text files?, a. read(), b. readcharacters(), c. readall(), d. readchar(), Correct answer:a, , 31, , Which function is used to read all the lines?, a. read(), b. readall(), c. readlines(), d. readline(), Correct answer:c, , 32, , In which format does the readlines() function give the output?, a. Integer type, b. list type, c. string type, d. tuple type, Correct answer:b, , 33, , In which format does the read() function give the output?, a. Integer type, b. string type, c. list type, d. tuple type, Correct answer:b, , 34, , Which function is used to write a list of strings in a file?, a. writestatement(), b. writelines(), c. writefulline(), d. writeline(), Correct answer:b, , 35, , Which function is used to write all the characters?, a. writechar(), b. writecharacters(), c. write(), d. writeall(), Correct answer:c, , 36. What is the correct syntax of open() function?, a. file=open(file_name[,access_mode][,buffering]), KVSRO ERNAKULAM 106
Page 115 :
107, b. fileobject=open(file_name[,access_model][,buffering]), c. fileobject=filename.open(), d., none of the mentioned, , Correct answer:b, 37, , In file handling, what does means “r”, “a”?, a. append, read, b. read, append, c. read, add, d. None of the mentioned, Correct answer:b, , 38, , The default file open mode is…., a. w, b. r+, c. w+, d. r, Correct answer:d, 39. What is the difference between r+ and w+ modes?, a., b., c., d., , In r+ mode, file length truncates to zero., In w+ mode, file length truncates to zero either file exists or not., No difference, Depends on the operating system, , Correct answer:b, 40. A file maintains a, , which tells the current position in the file where writing or, , reading will take place., a. line, b. file pointer, c. list, d. order, , 41, , 42, , Correct answer:b, Which of the following statements is true regarding the opening modes of a file?, a. While opening a file for reading, if the file does not exist, an error occurs., b. While opening a file for writing ,if the file does not exist, an error occurs., c. While opening a file for reading, if the file does not exist, a new file is created., d. None of the above., Correct answer:a, To force python to write the contents of file buffer on to storage file, .................... method, may be used., a. buffer(), b. flush(), c. close(), d. write(), Correct answer:b, , KVSRO ERNAKULAM 107
Page 116 :
108, 43, , Correct option to fill the line 1, a.csv, b.CSV, c.PICKLE, d.pickle, , Correct answer:d, 44. Choose correct statement for line 2 ., a.wb, b.ab, c.w, d.a, , 45, , Correct answer:b, Select correct statement to write data into file for line3 ., a.pickle.dump(record,file), b.pickle.dump(record), c.pickle.dump(file,record), d.pickle.load(record,file), , Correct answer:a, , KVSRO ERNAKULAM 108
Page 117 :
109, 46., , Fill in the blank in statement-1, a)w, b).ab, c)a, d).r, , Correct answer:d, 47. Fill in the blank in statement-2 to read the data from the file., a.File.Read(), b.file.read(), c.read.lines( ), d.readlines( ), , Correct answer:b, 48. Fill in the blank in statement-3 to read data word by word., a.Line.Split(), b.Line.split(), c.line.split(), d.split.word(), , Correct answer:c, 49. Fill in the blank in statement-4, which display the word having lesser than 4characters, a.len(c) ==4, b.len(c)<4, c.len ( )= =3, d.len ( )=3, , Correct answer:d, , KVSRO ERNAKULAM 109
Page 118 :
110, 50., , choose correct option for line 1, a.readline(), b.read(file), c.read(), d.readlines(), , Correct answer:c, 51. choose correct option for line 2, a.file, b.data, c.story, d.data.split(), , Correct answer:b, 52. choose correct option for line 3, a.Aa, b.['A','a'], c.aA, d.data, , Correct answer:b, 53. choose correct option for line 4, a.file.AMCount(), b.AMCount, c.AMCount(), d.AMCount(story.txt), , Correct answer:c, KVSRO ERNAKULAM 110
Page 119 :
111, 54., , choose correct option for line 1, a.file.read(), b.readline(), c.file.readlines(), d.file.readline(), , Correct answer:c, 55. choose correct option for line2- initialize the variable for count, a.c=0, b.c=c+1, c.both, d.none, , Correct answer:a, 56. choose correct option for line3, i=='T', i[0]=='T', "i"==T, i[0]==T, , Correct answer:b, 57, , complete the line4, a.c, b.count, c.i, d.data, , Correct answer:a, , KVSRO ERNAKULAM 111
Page 120 :
112, , Binary Files, ● Binary file(used to store binary data such as images, video files, audio files, etc.) is a non-text file. It contains data as 1s and 0s(computer readable, format)., ● Binary files are processed byte by byte., ● There is no delimiter and EOL character in the binary file., ● Binary files are faster in processing and consumes less memory compared to, text files., ● Extension of binary files .bin(.dat allowed?), ● pickle module is offering functions(dump and load) to operating binary files., ● File opening mode must attach ‘b’ to it for operating binary file(Ex: ‘rb’- for, reading), Basic operations with binary files:, a. Reading data from a file, b. Writing data to a file, c. Appending data to a file, d. Deleting a file, , Binary file, Basic operations, on a binary file, open using file open, modes, • rb, rb+, • wb, wb+, • ab, ab+, , File, Operations, , Modules and, Methods, , Read, operations in, a binary file, , import pickle, module, , write/create, , dump(), method, , search, , load(), method, , close a binary file, , append and, update, , KVSRO ERNAKULAM, , 112
Page 121 :
113, , SECTION - A, 1. Which of the following statement opens a binary file record.bin in write mode and, writes, data from a list lst1 = [1,2,3,4] on the binary file?, a. with open('record.bin','wb') as myfile:, pickle.dump(lst1,myfile), b. with open('record.bin','wb') as myfile:, pickle.dump(myfile,lst1), c. with open('record.bin','wb+') as myfile:, pickle.dump(myfile,lst1), d. with open('record.bin','ab') as myfile:, pickle.dump(myfile,lst1), 2. Which module is required to use built in function dump(), (a) Math (b)flush (c)pickle (d)csv, 3.Which of the following function is used to write data in binary mode?, (a)write (b)output (c)dump (d)send, 4.To read 2 characters from file object f1 command should be, (a)f1.read(2) (b)f1.read() (c)f1.readline() (d) f1.readlines(), 5.To get byte position from the beginning of file, function used is (a)seek (b)tell (c)read (d)write, 6.The file pointer, used to go to particular position, (a)seek (b)tell (c)read (d)write, 7.If a file is opened for reading, which of the following statements is not true?, a. The file must exist on the disk on the specified path, b. If the file exists at the specified path, the file is successfully opened., , KVSRO ERNAKULAM, , 113
Page 122 :
114, , c. The file even if at a different location on disk other than the specified path, will get, opened, d. Python gives error if the file does not exist at the specified path, Answer : c) The file even if at a different location on disk other than the, specified path, will get opened., 8.To read 24 characters from a file object infi, we use, a. Infi.read() b. infi.read(24), c. Infi.readline() d. infi.readlines, Answer: b) infi.read(24), 9.The readlines() method returns__________, a. a str b. a list of integers, c. a lit of single characters d. a list of lines, Answer : d) a list of lines., 10.Which of the following is not a valid mode to open a file., a. ab b. rw, c. wb d.w+, Answer : b) rw, 11.Which of the following functions do you use to write data in the binary format?, a. Write() b. output(), c. dump() d. send(), Answer : c) dump()., 12.Which of the following commands can be used to read the entire contents of a file, as a string using the file object <tmpfile>?, a. tmpfile.read(n), b. tmpfile.read(), c. tmpfile.readline(), KVSRO ERNAKULAM, , 114
Page 123 :
115, , d. tmpfile.readlines(), Answer : b. tmpfile.read(), 13.Which of the following command is used to open a file “c:\temp.txt” for writing in, binary format only?, a. outfile = open(“c:\temp.txt”, “w”), b. outfile = open(“c:\\temp.txt”, “wb”), c. outfile = open(“c:\temp.txt”, “w+”), d. outfile = open(“c:\\temp.txt”, “wb+”), Answer : b. outfile = open(“c:\\temp.txt”, “wb”), 14._____________ is the process of converting Python object hierarchy into a byte, stream so that it can be written into a file., a) Pickling, b) Unpickling, c) Dumping, d) Loading, Answer: a, 15._______ is the process of reading from a binary file, a) Pickling, b) Unpickling, c) Dumping, d) Loading, Answer: b, 16.___________ of pickle module will unpickle the data coming from the binary file., a) load(), b) dump(), KVSRO ERNAKULAM, , 115
Page 124 :
116, , c) writer(), d) insert(), Answer : a, 17.___________ of pickle module will pickle the data in the binary file., a) load(), b) dump(), c) writer(), d) insert(), Answer : b, 18._______________ will return the current position of file pointer in the file, a) seek(), b) search(), c) tell(), d) print(), Answer : c, 19.________ places the file pointer at the specified position in the open file., a) seek(), b) search(), c) tell(), d) print(), Answer : a, 20.F.seek(20,0) will move the file pointer 20 bytes in forward direction from, beginning of file. State True or False, a) True, b) False, , KVSRO ERNAKULAM, , 116
Page 125 :
117, , Answer : a, 21.F1.seek(-5,1) will move the file pointer 5 bytes backwards from end of file., State True or False, a) True, b) False, Answer : b, 22.Syntax of seek function in Python is myfile.seek(offset, reference_point) where, myfile is the file object. What is the default value of reference_point?, a) 0, b) 1, c) 2, d) 3, Answer : a, 23. Which of the following statements is true?, a) pickling creates an object from a sequence of bytes, b) pickling is used for object serialization, c) pickling is used for object deserialization, d) pickling is used to manage all types of files in Python, Answer : b, 24. “wb”, , mode in file handling also can be written as, , (a) w*b, , (b) w/b, , (c) w+b, , (d) none of these, , 25. What is unpickling?, (a) It is used for object serialization, , (b) It is used for object deserialization, , (c) None of the mentioned, , (d) All of the mentioned, , 26. What is the extension of binary file, KVSRO ERNAKULAM, , 117
Page 126 :
118, , (a).dat, , (b).txt, , (d).file, , (c).bin, , 27. Identify the invalid mode from the following., (a) a, , (b) r+, , (c) ar+, , (d) w, , 28.Which value will be shown if you try to open a binary file using a text, (a) Default value, , (b) Advance Value, , (c) Garbage value, , (d) Parameter Value, , 29.Binary file is stored in terms of, (a) bit, , (b) bytes, , (c) nibble, , (d) mnemonics, , 30.Mode used for reading from pickle file is, (a) rb, , (b) r, , (c) br, , (d) read, , 31. When file is opened as “with open” then file __________ automatically., , (a) reads, , (b) writes, , (c) closes, , (d) opens, , 32.Which of the following commands is used to open the file “STUDENT.DAT” for writing, only in binary format?, (a) F= open(“STUDENT.DAT”,’wb’), , (b) F= open(“STUDENT.DAT”,’w’), (c) F= open(“STUDENT.DAT”,’wb+’), (d) F= open(“STUDENT.DAT”,’w+’), 33. Which of the following commands is used to write the list L into the binary file,, STUDENT.DAT?, (a) pickle.write(L,f), (b) pickle.write(f, L), (c) pickle.dump(L,F), , (d) f=pickle.dump(L), 34.Which of the following commands is used to read each record from the binary file, STUDENT.DAT?, , KVSRO ERNAKULAM, , 118
Page 127 :
119, , (a) R = pickle.load(F), , (b) pickle.read(r,f), (c) r= pickle.read(f), (d) pickle.load(r,f), 35.Which of the following file mode opens a file for append or read a binary file and moves, the files pointer at the end of the file if the file already exist otherwise create a new file?, (a) a, , (b) ab, , (c) ab+, , d) a+, , 36.Which of the following statement(s) are correct regarding the file access modes?, (a) ‘r+’ opens a file for both reading and writing. File object points to its beginning., , (b) ‘w+’ opens a file for both writing and reading. Adds at the end of the existing file if, it exists and creates a new one if it does not exist., (c) ‘wb’ opens a file for reading and writing in binary format. Overwrites the file if it, exists and creates a new one if it does not exist., (d) ‘a’ opens a file for appending. The file pointer is at the start of the file if the file, exists., 37.The syntax for dump () method, 1. dump(data_object, file_object), 2. dump[data_object, file_object], 3. dump[file_object], 4. dump[data_object], 38. Binary files represent the actual content, (a)image, (b), audio (c) video, (d) All of these, 39.The process by which a pythonobject is converted to a byte stream is called as, (a)Unpicking, (b), loading, (c), pickling, (d), Dumping, 40.Which of the following statements correctly explain the function of seek() method?, (a) tells the current position within the file., (b) determines if you can move the file position or not., (c) indicates that the next read or write occurs from that position in a file., KVSRO ERNAKULAM, , 119
Page 128 :
120, , (d) moves the current file position to a given specified position, , 41.What is ‘f’ in the following statement?, f=open("Data.txt" , "r"), (a) File Name (b) File Handle (c)Mode of file(d)File Handling, , SECTION - B, 1. The, , following code has some errors. Identify the error line(s), , import pickle, f = open (‘example.dat’, rb), f.dump([2,3,4]), f.close(), (a) Line 1 and 2 have the errors, (b) Lines 3 and 4 have errors, (c) Line 2 and 3 have the errors, , (d) Lines 2 has error, 2. Rahul is trying to read data from a binary file test.bin and store it into, List L. Consider the following code written by him., , import pickle as p, with open(‘test’,’rb’) as f:, _________________ #statement 1, Identify the missing code in Statement 1., (a) f=p.load(L), , (b) p=p.load(L), , (c) L=p.load(f), , (d) f=L.load(p), , 3. What is the output produced by the following code:, , KVSRO ERNAKULAM, , 120
Page 129 :
121, , import pickle, score =[10,20,30,40,50,60], with open('test.dat','wb') as fout:, for ix in score:, pickle.dump(ix,fout), size=0, with open('test.dat','rb') as fin:, num=pickle.load(fin), size+=num, num=pickle.load(fin), print(size,end=','), num=pickle.load(fin), size+=num, print(size), (a)10, 50, , (b) 10, 40, , (c). 20, 50, , (d). 10, 60, , 4. What will be displayed by the following code?, , import pickle, colors=['red','green','blue','grey','pink'], with open('test.dat','wb') as fout:, pickle.dump(colors,fout), with open('test.dat','rb') as fin:, lst=pickle.load(fin), KVSRO ERNAKULAM, , 121
Page 130 :
122, , print(lst[1:5:2]), (a) ['green', 'blue'] (b)[‘red’, ‘blue’], ‘green’], 5. The, , (c) ['green', 'grey'], , (d), , [‘red’,, , binary file STOCK.DAT is containing following fields, , SName and Price, Function Billing() is created in Python to read each record of a pickled file, STOCK.DAT, and display the Total Price of all the records in the file., import pickle, def Billing():, file=open(‘STOCK.DAT’,’rb’), IRec=pickle.load(file) #To read the object from file, Totprice=0, for I in IRec:, ___________, print (Totprice), file.close(), Choose appropriate statement to calculate the total price from the, following:, (a) Totprice=I[1], , (b) Totprice=+I[1], , (c) Totprice+=I[1], , (d) Totprice=I+Totprice, , 6. When function SPLDOCS() is executed, it display all the content from a, pickled file DOCS.DAT, where Specialisation of DOCTORS is, KVSRO ERNAKULAM, , 122
Page 131 :
123, , “CARDIOLOGY”., , def Disp(s):, print (s.Name,”#”,s.Specialisation), def SPLDOCS():, D=DOCTORS(), file=open(‘DOCS.DAT’,’rb’), try:, while True:, D=pickle.load(file), if D.Specialisation == ‘CARDIOLOGY’:, ________, except EOFError:, pass, file.close(), To fill the missing statement 1, choose the statement to call function Disp, (a) D[Disp()], , (b) D.Disp(), , (c) Disp(D), , (d) Disp[D], , 7. Sunil is writing a program to search for the details a particular student., He has got difficulties in completing the code. Help him to, complete, it., ______ open(‘student’,rb) as ______:, Complete the open() statement, , KVSRO ERNAKULAM, , 123
Page 132 :
124, , (a) filehandle, filename (b). filename, filehandle, (d) with,filename, , (c) with, filehandle, , 8. Aman, wants to read pickled file ELECTION.DAT and displays, every such Name whose Count is less than 10 but facing some problems, to give the condition., , The File contains the following fields :Name,Count, import pickle, def cLowCount():, file=open(‘ELECTION.DAT’,’rb’), ERec=pickle.load(file) #To read the object from file, for E in ERec:, if __________: # statement 1, print (E[0] ), file.close(), Choose the correct option which satisfied the condition., (a) E<10, , (b), , E[2]<10, , (c) E[1]<10, , (d) E[0]<10, , 9. Observe, the below code and write which of the following is, converting the, list into bytes is, , list1 = [23, 43, 55, 10, 90], newFile = open("binaryFile", "wb"), newFile.write(bytearray(list1)), newFile.close(), (a) byte array(), , (b) newFile (c) write, , (d) wb, KVSRO ERNAKULAM, , 124
Page 133 :
125, , 10., Raghav, is trying to write an object obj1 = (1,2,3,4,5) on a, binary file “test.bin”. Consider the following code written by him., , import pickle, obj1 = (1,2,3,4,5), myfile = open(“test.bin”,’wb’), pickle. #Statement 1, myfile.close(), Identify the missing code in Statement 1., (a) dump(myfile,obj1), (b) dump(obj1, myfile), , (c) write(obj1,myfile), (d) load(myfile,obj1), , 11. . Raghav is trying to write a tuple tup1 = (1,2,3,4,5) on a binary file test.bin., Consider the, following code written by him., import pickle, tup1 = (1,2,3,4,5), myfile = open("test.bin",'wb'), pickle._______ #Statement 1, myfile.close(), , Identify the missing code in Statement 1., KVSRO ERNAKULAM, , 125
Page 135 :
127, , When the above mentioned function, display (103) is executed, the output displayed, is, 190000., Write appropriate jump statement from the following to obtain the above output., a. jump, b. break, c. continue, d. return, , SECTION - C, 1. Arun, during Practical Examination of Computer Science, has been, assigned an incomplete search() function to search in a pickled file, student.dat. The File student.dat is created by his Teacher and the, following information is known about the file., • File contains details of students in [roll_no,name,marks] format., • File contains details of 10 students (i.e. from roll_no 1 to 10) and separate, list of each student is written in the binary file using dump()., Arun has been assigned the task to complete the code and print details of, roll number1., def search(r):, f = open(“student.dat”,____) #Statement-1, ____: #Statement-2, while True:, rec = pickle.____ #Statement-3, KVSRO ERNAKULAM, , 127
Page 136 :
128, , if(____): #Statement-4, print(rec), except:, pass, ____ #Statement-5, (i) In which mode Arun should open the file in Statement-1?, (a) r, , (b) r+, , (d) wb, , (c) rb, , (ii) Identify the suitable code to be used at blank space in line marked as, Statement2, (a) if(rec[0]==1), , (b) for i in range(10), , (c) try, , (d) pass, , (iii) Identify the function (with argument), to be used at blank space in, line marked as Statement-3., (a) load(), , (b) load(student.dat), , (c) load(f), , (d) load(fin), , (iv) What will be the suitable code for blank space in line marked as, Statement-4., (a) rec[0]=r (b) rec[1]==r, , (c) rec[2]=r, , (d) rec[0]==r, , (v) Which statement Arun should use at blank space in line marked as, Statement4 to close the file., (a) file.close(), close(), , (b) close(file), , (c) f.close(), , (d), , 2. Arun, during Practical Examination of Computer Science, has been, assigned, an incomplete search() function to search a record which is, passed as parameter in a pickled file student.dat. The File student.dat is, , KVSRO ERNAKULAM, , 128
Page 137 :
129, , created by his Teacher and the following information is known about the, file., (a) File contains details of students in [roll_no,name,marks] format., (b) File contains details of 10 students (i.e. from roll_no 1 to 10) and, separate list of each student is written in the binary file using dump()., Arun has been assigned the task to complete the code and print details of, roll number1., def search(r):, f = open(“student.dat”,____), , #Statement-1, , ____:, , #Statement-2, , while True:, rec = pickle.____, , #Statement-3, , if(____):, , #Statement-4, , ________, , #Statement-5, , except:, pass, ____, , #Statement-6, , i. In which mode Arun should open the file in Statement-1?, (a) r, , (b) r+, , (c) rb, , (d) wb, , ii. Identify the suitable code to be used at blank space in line marked as, Statement2., (a) Try, , (b) while True, , (c) try, , (d) pass, , iii. Identify the function (with argument), to be used at blank space in line, marked as Statement-3., (a) load(), , (b) f.load(), , (c) load(f), , (d) f(load), KVSRO ERNAKULAM, , 129
Page 138 :
130, , v. What will be the suitable code for blank space in line marked as, Statement-4., a) rec(0)==r (b) rec[1]==’r’ (c) rec[1]==r (d) rec[0]==r, v. What will be the suitable code for blank space in line marked as, Statement-5 to show record?, (a) show(rec), rec(print), , (b) print(rec), , (c) print.rec(), , (d), , vi. Which statement Arun should use at blank space in line marked as, Statement5 to close the file?, (a) file.close(), , (b) close(file), , (d) close(), , (c) f.close(), , ., 3. Ms. Suman is working on a binary file and wants to write data from a, list to a binary file. Consider list object as l1, binary file suman_list.dat,, and file object as f., i ) Which of the following can be the correct statement for her?, a) f = open(„suman_list‟,‟wb‟); pickle.dump(l1,f), b) f = open(„suman_list‟,‟rb‟); l1=pickle.dump(f), c) f = open(„suman_list‟,‟wb‟); pickle.load(l1,f), d) f = open(„suman_list‟,‟rb‟); l1=pickle.load(f), Correct Answer : a) f = open(„suman_list‟,‟wb‟); pickle.dump(l1,f), ii ) Which option will be correct for reading file for suman?, a )f = open(„suman_list‟,‟rb‟), b )f = open(„suman_list‟,‟r‟), c )f = open(„suman_list‟,‟r+‟), d )f = open(„suman_list‟,‟ab‟), KVSRO ERNAKULAM, , 130
Page 139 :
131, , Correct Answer : a) f = open(„suman_list‟,‟rb‟), iii ) In which of the file mode existing data will be intact in binary file?, a) a, b) ab, c) w, d) wb, Correct Answer : b) ab, , iv ) Which one of the following is correct statement?, a) import – pickle, b) pickle import, c) import pickle, d) All of the above, Correct Answer : c ) import pickle, v) What are the binary files used for?, a. It is used to store data in the form of bytes., b. To store data, c. To look folder good, d. None of these, Correct Answer : a) It is used to store data in the form of bytes, 4.Ms. Sejal is working on the sports.dat file but she is confused about, how to complete the code to read the data from the binary file. Suggest a, suitable line for her to fulfil her., KVSRO ERNAKULAM, , 131
Page 140 :
132, , ____________ # Statement 1, def sports_read ():, f1 = _______________ # Statement 2, _________________ # Statement 3, print(data), f1. close (), sports.read(), i ) Identify the suitable code for blank space in line marked as Statement1., a. pickle import, b. import pickle, c. import.pickle, d. None of these, Correct Answer : b) import pickle, ii ) Identify the suitable code for blank space in line marked as, Statement-2., a. open("sports.dat","wb"), b. open("sports.dat","r"), c. open("sports.dat","rb"), d. None of these, Correct Answer : c) f1 = open("sports.dat","rb"), iii ) Identify the suitable code for blank space in line marked as, Statement-3., a. data = pickle.load(f1), KVSRO ERNAKULAM, , 132
Page 141 :
133, , b. data = pickle.dump(f1), c. data = pickle.load(f), d. data = pickle.dump(f), Correct Answer: a) data = pickle.load(f1), iv ) What is the description of `r+b` in binary mode?, a. read and write, b. write and read, c. read only, d. none of these, Correct Answer : a) read and write, v )Which of the following file modes will not delete the existing data in, binary file ?, a. wb, b. w, c. a, d. ab, Correct Answer : d) ab, 5.Saritha is trying to add data onto a existing binary file and is facing, difficulty in, completing the code.Help her to fill the gaps in the code., Incomplete Code:, import pickle, print("WORKING WITH BINARY FILES"), _____________________________ # Statement 1, KVSRO ERNAKULAM, , 133
Page 144 :
136, , b. bfile.close, c. file.close(), d. none of these, Correct Answer : a) bfile.close(), v ) Which of the following is the correct syntax to read from a file using, load function ?, A. pickle.load(<filehandle>), B. <object> - load.pickle(<filehandle>), C. <object> - pickle.load(<filehandle>), D. All of the above, Correct Answer : c) <object> - pickle.load(<filehandle>), 6.A Binary file Stock.dat has a structure [pno,pname,qty,price].A user, defined function Createfile() to input data for 3 records and add to, stock.dat .There are some blanks help in filling the gaps in the code:, Incomplete Code :, Import ___________ # Statement 1, def createfile():, File=open(“d:\\Stock.dat”,‟____‟) #Statement 2, pno=input(“Enter product no:”), pname= input(“Enter product name:”), qty= input(“Enter product quantity:”), price= input(“Enter product price:”), record=[pno,pname,qty,price], _______________ # Statement 3, KVSRO ERNAKULAM, , 136
Page 145 :
137, , Print(“Record inserted”), File.close(), Createfile(), i ) Identify the suitable code for blank space in line marked as Statement1., a. csv, b. CSV, c. pickle, d. PICKLE, Correct Answer : c) pickle, ii ) Identify the suitable code for blank space in line marked as, Statement-2., a. wb, b. ab, c. w, d. a, Correct Answer : b) ab, iii ) select correct statement to write data into file for Statement-3., a. pickle.dump(record,file), b. pickle.dump(record), c. pickle.dump(file,record), d. pickle.load(record,file), Correct Answer: a) pickle.dump(record,file), iv ) Which method is used for object deserialization ?, KVSRO ERNAKULAM, , 137
Page 146 :
138, , A. Pickling, B. Unpickling, C. All of the above, D. None of the above, Correct Answer : b) Unpickling, V )What is the last action that must be performed on a file? *, a. save, b. close, c. end, d. write, Correct Answer : b) close, , 7.A binary file “STUDENT.DAT” has structure [admission_number, Name,, Percentage]. Write a function countrec() in Python that would read, contents of the file “STUDENT.DAT” and display the details of those, students whose percentage is above 75. Also display number of students, scoring above 75%., ________ pickle # line1, def countrec():, fobj=open("_____________","rb”) # line2, num = 0, try:, while ______: # line3, rec=pickle.load(fobj), , KVSRO ERNAKULAM, , 138
Page 147 :
139, , if rec[2]>75:, num = num + 1, print(rec[0],rec[1],rec[2]), except:, fobj.close(), return num, i ) Identify the suitable code for blank space in line-1., a. import, b. IMPORT, c. Import, d. None of the above, Correct Answer : a) import, ii ) Identify the suitable code for blank space in line 2., a. STUDENT.DAT, b. STUDENTS.DAT, c. SCHOOL.DAT, d. None of the above, Correct Answer : a) STUDENT.DAT, iii ) select correct keyword to fill for line-3., a. True, b. False, c. true, d. TRUE, KVSRO ERNAKULAM, , 139
Page 148 :
140, , Correct Answer: a) True, , 6.Ms.Anitha is unable understand what can be the output of the following, code.Help her in getting the output., Import pickle, L=[20,40,50], f=open(“list.dat”,‟wb‟), Pickle.dump(l,f), Print(“Data added successfully”), f.close(), f=open(“list.dat”,‟rb‟), data=pickle.load(f), f.close(), print(data), a. Data added successfully, [20,40,50], b. [20,30,50], Data added successfully, c. [20,30,50], d. No output, Correct Answer: a) Data added successfully, [20,40,50], 8.A binary file “salary.DAT” has structure [teacherid, teacher name,, salary]. Complete the code in the blanks so that it would read contents of, KVSRO ERNAKULAM, , 140
Page 149 :
141, , the file “salary.DAT” and display the details of those teachers whose, salary is above 20000., import pickle, ____________________________ # line1, try:, print("tr id\t tr Name\t tr Sal"), while True:, rec=___________.load(fobj) #line2, if rec[2]>_______: #line3, print(rec[0],"\t\t",rec[1],"\t\t",rec[2]), except:, ____.close() #line 4, i ) To open the file for writing the data in line marked as line-1., a. fobj=open("salary.dat","rb"), b. fobj=open("salary.dat","r"), c. fobj=open("salary.dat","r+"), d. fobj=open("data.dat","rb"), Correct Answer : a) fobj=open("data.dat","rb"), ii ) The module used in line2, a. PICKLE, b. pickling, c. pickle, d. None of these, KVSRO ERNAKULAM, , 141
Page 150 :
142, , Correct Answer : c) pickle, iii ) Identify the salary to be checked in the code marked as line-3., a. 50000, b. 20000, c. 24000, d. 10000, Correct Answer: b) 20000, iv ) Which of the following File Modes creates a new file, if the file does, not exist?, (choose one/more), a. „r‟, b. „bw‟, c. „w‟, d. „a‟, Correct Answer : c) w, v ) What is true about Binary files, a. They are not human readable, b. the file extension is .dat, c. the file stores same format as held in memory., d. All of the above, Correct Answer : d) All of the above, 8.Mr.Rohan wants to modify salary of employee having a, structure[eid,ename, , KVSRO ERNAKULAM, , 142
Page 151 :
143, , ,salary],but unable to fill the gaps in the code. Help him to complete the, code, Import pickle, f = open('d:/student.dat','rb'), reclst = [], r=___________________________ # line 1 code to ask employee id, m=int(input(“enter correct salary”)), while True:, try:, rec = pickle.load(f), reclst.append(rec) #line2 statement to add items in list at the end, one by, one, except EOFError:, break, f.close(), for i in range (len(reclst)):, if reclst[i]['eid']==r:, reclst[i]['salary'] = m, f = open('d:/student.dat','___') #line 3 mode to be used to copy the, data, for x in reclst:, pickle.dump(x,f), f.close(), KVSRO ERNAKULAM, , 143
Page 152 :
144, , i ) Identify the code in line1., a. int(input(“Enter employee id”)), b. int(“Enter employee id”), c. int(INPUT(“Enter employee id”)), d. None of the above, Correct Answer : a) int(input(“Enter employee id”)), , ii ) The module used in line2, a. PICKLE, b. pickling, c. pickle, d. None of these, Correct Answer : c) pickle, iii ) Fill in the code marked as line-3., a. w, b. wb, c. r, d. Rb, Correct Answer: b) wb, 9.A binary file sports.dat contains information in the following structure:(, Event, Participant ) A code is shown below which is incomplete that, would read contents from the sports.dat and creates a file named, , KVSRO ERNAKULAM, , 144
Page 154 :
146, , d. None of these, Correct Answer : c) dump, iii ) Information stored on a storage device with a specific name is called, as __________., a. array, b. dictionary, c. file, d. Tuple, Correct Answer: c) file, iv) Which of the follwong is not a valid mode to open a file?, a . ab, b. rw, c . r+, D.w+, Correct Answer: b) rw, 10.A function searchprod( pc) in python is created to display the record, of a particular product from a file product.dat whose code is passed as, an argument. Structure of product contains the following elements, [product code , product price].There is some problem in completing the, code,help to finish the code:, f = ________('d:/product.dat','rb') #line1, flag = False, pc=input(“Enter product code to be searched”), while True:, try:, KVSRO ERNAKULAM, , 146
Page 155 :
147, , rec = pickle.load(f), if rec['pcode'] ==_____: #line2, print('Product code:',rec['pcode']), print('Price:',rec['price']), flag = True, except EOFError:, break, if flag == False:, print('No Records found'), f.close(), i ) Identify the method in line1., a. close, b. open, c. OPEN, d. None of the above, Correct Answer : b) open, ii ) The variable used to accept product code entered by the user for the, line2, a. pcode, b. pc, c. code, d. None of these, Correct Answer : b) pc, KVSRO ERNAKULAM, , 147
Page 156 :
148, , 11.Archit wants to create and display a Binary file named “Myfile.DAT”., Complete the missing code to open, create and display the file., import __________ #Line1, double=[], for i in range(1,11):, double.append(2*i), fo=__________________ #Line2, pickle.________________ #Line 3, fo.close(), fin=___________________ #Line4, result=________________ #Line 5, fin.close(), print(" The content of file :", result), 1. Name the module he should import in Line 1., a) csv, b) pickle, c) binary, d) bin, Answer : b, 2. Fill in the blank in Line 2 to open the file for writing the contents of the, file., a) open("Myfile.dat","w"), b) open("Myfile.dat","r"), c) open("Myfile.dat","wb"), KVSRO ERNAKULAM, , 148
Page 157 :
149, , d) open("Myfile.dat","rb"), Answer : c, 3. Fill in the blank in Line 3 with the function to write entire contents to, file., a) load(double,fo), b) dump(double,fo), c) writer(double), d) insert(double,fo), Answer : b, 4. Fill in the blank in Line 4 to open the file for displaying contents of file., a) open("Myfile.dat","w"), b) open("Myfile.dat","r"), c) open("Myfile.dat","wb"), d) open("Myfile.dat","rb"), Answer : d, 5. Fill in the blank in Line 5 read the contents of the file., a) pickle.read(fin), b) pickle.readline(fin), c) pickle.readlines(fin), d) pickle.load(fin), Answer: d, 12.Rohith has been given the following incomplete code for entering his, details(Name,contact number and address) to a file “Personal.DAT” and, , KVSRO ERNAKULAM, , 149
Page 158 :
150, , display the contents. Complete the missing code to open, create and, display the file., import __________ #Line1, mydata=[], name=input(“Enter Name:”), contactno=int(input(“Enter contact number:”)), address=input(“Enter address:”), mydata=[name,contactno,address], f1=__________________ #Line2, pickle.________________ #Line 3, f1.close(), f2=___________________ #Line4, result=________________ #Line 5, f2.close(), print(" The content of file :", result), 1. Name the module he should import in Line 1., a) csv, b) pickle, c) binary, d) bin, Answer : b, 2. Fill in the blank in Line 2 to open the file for writing the contents of the, file., a) open("Personal.dat","w"), KVSRO ERNAKULAM, , 150
Page 160 :
152, , 13.You are provided with some incomplete code for entering student‟s, details (Rollno,, Name and marks) to a file “Student.DAT” and display the contents., Complete the, missing code to open, create and display the file., import __________ #Line1, data=[], rollno=int(input(“Enter Roll number:”)), name=input(“Enter Name:”), marks=int(input(“Enter mark:”)), data=[rollno,name,marks], fout= open("Student.dat","wb"), pickle.________________ #Line 2, fout.close(), fin=___________________ #Line3, output=________________ #Line 4, fin.close(), if ____________>=33: #Line5, print(output[1]," passed”), else:, print(output[1]," failed”), 1. Name the module to import in Line 1., a) csv, b) pickle, KVSRO ERNAKULAM, , 152
Page 161 :
153, , c) binary, d) bin, Answer : b, 2. Fill in the blank in Line 2 with the function to write entire contents to, file., a) load(data,fout), b) dump(data,fout), c) writer(data), d) insert(data,fout), Answer : b, 3. Fill in the blank in Line 3 to open the file for displaying contents of file., a) open("Student.dat","w"), b) open("Student.dat","r"), c) open("Student.dat","wb"), d) open("Student.dat","rb"), Answer : d, 4. Fill in the blank in Line 4 read the contents of the file., a) pickle.read(fin), b) pickle.readline(fin), c) pickle.readlines(fin), d) pickle.load(fin), Answer: d, 5 . Fill in the blank in Line 5 to display he status of, students(passed/failed) based on their mark., KVSRO ERNAKULAM, , 153
Page 162 :
154, , a) Output[0], b) Output[1], c) Output[2], d) output, Answer : c, , 14.Ritesh wants to perform the following binary file operations, as a part, of his assignment, with the help of two user defined functions/modules:, a. AddEmp() to create a binary file called Employee.DAT containing, employee information – employee number, name and salary., b. ViewEmp() to display the name and salary of employees who are, getting Rs.50000 above as salary. The function should also display the, average salary. Help him in filling incomplete code., , import pickle, def AddEmp():, _______________#Line1 to open the binary file to write data, while True:, Empno = int(input("Employee number: :")), Name = input("Name : "), Salary = int(input("Enter Salary :")), L = [Empno, Name, Salary], #Line2 to write the list L into the file, KVSRO ERNAKULAM, , 154
Page 164 :
156, , print("average Salary = ",average), AddEmp(), ViewEmp(), 1. Write statement #Line1, to open the file “Employee.DAT” for writing, only in binary format?, a) F= open("Employee.DAT",'wb'), b) F= open("Employee.DAT",'w'), c) F= open("Employee.DAT",'wb+'), d) F= open("Employee.DAT",'w+'), Answer : a, 2. Write statement, #Line2, to write the list L into the binary file,, Employee.DAT?, a) pickle.write(L,f), b) pickle.write(f, L), c) pickle.dump(L,F), d) f=pickle.dump(L), Answer : c, 3. Write statement, #Line3, to read each record from the binary file, Employee.DAT?, a) R = pickle.load(F), b) pickle.read(r,f), c) r= pickle.read(f), d) pickle.load(r,f), Answer : a, KVSRO ERNAKULAM, , 156
Page 165 :
157, , 4. Write statement , #Line4, to find employees who are getting salary, more than Rs.50000., a) R[0], b) R[1], c) R[2], d) R[3], Answer : c, 5. Write statement , #Line5, to find average salary of employees, a) Total/countrec, b) Total/C50K, c) Total/Countrec, d) average(Total), Answer : c, 15.Anand, a software developer, is asked to help a librarian to find some, details of books in his library. The book information is stored in a binary, file Books.DAT. Create two user defined functions/modules:, a. AddBook() to create a binary file called Books.DAT containing Book, information – Book name, Author and Price., b. ViewBook() to display the name, Author and price of books which are, more than Rs.350 in price. The function should also display the average, price of books., Try to fill the incomplete code to get required information for librarian., import pickle, def AddBook():, , KVSRO ERNAKULAM, , 157
Page 166 :
158, , __________#Line1 to open the binary file to write data, while True:, Name = input("Book Name : "), Author= input("Author Name :"), Price = int(input("Enter Book Price:")), Lst= [Name, Author, Price], #Line2 to write the list Lst into the file, Choice = input("enter more (y/n): "), if Choice in "nN":, break, Fp.close(), def ViewBook():, Total=0, Count=0, C=0, F=open(________________) #Line3 to open file for reading, while True:, try:, _____________#Line4 to read from the file, Count+=1, Total+=Row[2], if _______ > 350: #Line5, print(“Price of “,Row[1],"=, KVSRO ERNAKULAM, , 158
Page 167 :
159, , ",Row[2]), C+=1, , except:, break, , if C==0:, print("All books are having price less than 350"), avgprice=Total/Count, print("Average Price = ",avgprice), F.close(), AddBook(), ViewBook(), 1. Fill in the blank in Line1, to open the file “Books.DAT” for writing in, binary format?, a) Fp= open("Books.DAT",'w'), b) Fp= open("Books.DAT",'wb'), c) Fp= open("Books.DAT",'wb+'), d) Fp= open("Books.DAT",'w+'), Answer : b, 2. Fill in the blank in Line2, to write the list Lst into the binary file,, Books.DAT?, a) pickle.write(Lst,fp), b) pickle.write(fp, Lst), KVSRO ERNAKULAM, , 159
Page 168 :
160, , c) pickle.dump(Lst,Fp), d) fp=pickle.dump(Lst), Answer : c, 3. Fill in the blank in Line3, to open the file “Books.DAT” for reading, a) F= open("Books.DAT",'r'), b) F= open("Books.DAT",'r+'), c) F= open("Books.DAT",'wb+'), d) F= open("Books.DAT",'rb'), Answer : d, , 4. Fill in the blank in Line4, to read data from file., a) Row=pickle.load(Fp), b) Row=pickle.read(Fp), c) Row=pickle.read(F), d) Row=pickle.load(F), Answer : d, 5. Fill in the blank in Line5 with suitable expression:, a) Row[0], b) Row[1], c) Row[2], d) Row[3], Answer : c, , KVSRO ERNAKULAM, , 160
Page 169 :
161, , CSV Files, CSV stands for “Comma Separated Values.”, It is the simplest form of storing data in tabular form as plain text., Each line of the file is a data record., Each record consists of one or more fields, separated by commas., Default delimiter of CSV File is comma, Reading and writing CSV files can be done with the help of csv module in Python, , Features:, It is Easier to create, It is the preferred import and export format for databases and spread sheets, It is capable of storing large amount of data, , Module Used:, csv Module, , Functions Used :, open(), , :, , opens the csv file, , csv.writer(), , :, , returns writer object which writes data into csv file, , csv.writerow(), , :, , writes one row of data onto writer object, , csv.writerows() :, , writes multiple rows of data onto writer object, , csv.reader(), iterable object, , returns a reader object which loads data from CSV file into an, , :, , KVSRO ERNAKULAM, , 161
Page 170 :
162, , Multiple Choice Questions:, 1. CSV stands for :, a. Comma Separated Values, b. Comma Separated Variables, c. Comma Stored Values, d. Comma Stored Variables, 2. The separator character of CSV Files is called a, a. EOL, b. Delimiter, c. EOF, d. Default, 3. The default delimiter for a CSV file is :, a., Semi colon, b., Colon, c., Comma, d., Hyphen, 4. _____ module of Python provides the functionality to read and write tabular, data in CSV file., a. pickle, b. csv, c. file, d. ccv, 5. Which function is used to open a csv file ?, a. Open(), b. csv.open(), c. writer(), d. csv.writer(), 6. Name the function to read from CSV file., a. read(), b. csv.reader(), c. csv.read(), d. readline(), KVSRO ERNAKULAM, , 162
Page 171 :
163, , 7. Which among the following is not a function of csv module?, a. reader(), b. read(), c. writer(), d. writerows(), 8. In Python, default newline character is :, a. \f, b. \t, c. \n, d. \v, 9. CSV module allows to write multiple rows using ____________ function., a. writerows( ), b. . writerow( ), c. writer( ), d. None of the above, 10. The opening function of a csv file is similar to the opening of:, a. Binary file, b. Text File, c. Both of them, d. None of them, 11. The _____ argument of open function is to specify how Python handle the, newline characters in csv file, a. newline, b. line, c. mode, d. char, 12. Which among the following is an iterable object ?, a. writer, b. file, c. reader, d. All of the above, , KVSRO ERNAKULAM, , 163
Page 172 :
164, , 13. To specify a different delimiter while writing into a csv file, ______ argument, is used with writer object :, a. newline, b. separator, c. character, d. delimiter, 14. Which mode opens the file for exclusive creation, which fails in the case where, file already exists, a. a, b. w, c. x, d. r, 15. The file mode to open a CSV file for reading as well as writing is _____., a) a+, b) w+, c) r+, d) All the above., , 16.Identify the line number which may cause an error:, import csv #Line1, line=[[1,2,3],[4,5,6]]#Line 2, with open("sample.csv","w",newline="") as csvfile: #Line3, writer=csv.writer(csvfile,delimiter="|") #Line4, for line in writer: #Line5, writer.writerow(line), a. Line1, b. Line2, c. Line 4, d. Line 5, , KVSRO ERNAKULAM, , 164
Page 173 :
165, , 17. The CSV files are ____ files., a) Plain text file, b) Binary, c) Data, d) Python, , 18. The writer() function has how many mandatory parameters?, a. 1, b. 2, c. 3, d. 4, 19. Which of the following parameter needs to be added with open function to, avoid blank row followed by each record in the CSV file?, a. quotechar, b. quoting, c. newline, d. skiprow, 20. Ajaikrishna wants to separate the values by a $ sign. Suggests him a pair of, function and parameter to use it., a. open, quotechar, b. writer,quotechar, c. open,delimiter, d. writer,delimiter, , Case Study Based Questions:, , 21. Tejalakshmi of Class 12 have written the below code . Observe and fill in the, given blanks so that it opens the file “data.csv” and read and print all the, records., import csv, with _________ as f: #1, r = ______(f) #2, for row in ______: #3, print(_____) #4, KVSRO ERNAKULAM, , 165
Page 174 :
166, , I., , What must be filled in line 1?, a. Open(“data.csv”,”r”), b. open(“data.csv”), c. “data.csv”, d. File, , II., , What must be filled in Line 2?, a. csv.reader(), b. csv.read(), c. csv.write(), d. csv.writer(), , III., , IV., , V., , What must be filled in line 3?, a. data.csv, b. f, c. r, d. None, What must be filled in line 4?, a. data, b. f, c. “File”, d. row, What is the default data type of data read from this file?, a. List, b. String, c. Tuple, d. Integer, , KVSRO ERNAKULAM, , 166
Page 176 :
168, , Create_CSV(), Display_CSV(, I. Identify suitable code for the blank space in line marked as Statement-1., a) include, b) add, c) Import, d) import, , II. Identify the missing code for the blank space in line marked as Statement-2., a) Customer, b) reader, c) csvwriter, d) writer, III., , Identify the argument name for the blank space in line marked as, Statement-3?, a) Row, b) Rec, c) row, d) rec, , IV., , Identify the missing file name for the blank space in line marked as, Statement-4?, , a) customer, b) customer.csv, c) customer.txt, d) customer.dat, , KVSRO ERNAKULAM, , 168
Page 177 :
169, , V., , Identify the object name for the blank space in line marked as Statement-5?, , a) i, b) Rec, c) row, d) rec, 23. Daya of class 12 is writing a program to create a CSV file “empdata.csv”, with empid, name & mobile number. Also to search a particular empid and, display its record details. He has written the following code. As a, programmer, help him to successfully execute the given task., import ______#Line1, fields=['empid','name','mobile_no'], rows=[['101','Rohit','8982345659'],['102','Shaurya','8974564589']], filename="empdata.csv", f=open(filename,'w',newline=''), csv_w=________ #Line2, for row in rows:, csv_w. _______#Line3, f.close(), f=open(filename,'r'), csv_r=___________ #Line4, ans='y', while ans=='y':, found=False, emplid=input("Enter employee id to search="), for row in csv_r:, if len(row)!=0:, print(row[0]), if ______==emplid: #Line5, print("Name : ",row[1]), print("Mobile No : ",row[2]), found=True, break, if not found:, print("Employee id not found"), KVSRO ERNAKULAM, , 169
Page 178 :
170, , ans=input("Do you want to search more? (y)"), I. Choose the module he should import in Line 1., a) math, b) pickle, c) csv, d) random, , II. Choose a code to write the column heading from fields list in Line2., a) writerows(fields), b) writerow(field), c) writerow(fields), d) writerows(fields), , III. Choose a code to write the row from rows list in Line3., a) writerows(row), b) writerow(row), c) writerow(rows), d) write_row(row), , IV. Choose a code for line 4 to read the data from a csv file., a) csv.reader(f), b) csv.read(f), d) pickle.load(f), e) f.read(), , KVSRO ERNAKULAM, , 170
Page 179 :
171, , V. Choose the correct variable (list value) to check “emplid” in Line5., a) Row[0], b) Rec[0], c) row[0], d) rec[0], , 24. Viraj is making a software on “Countries and their Capitals” in which, various records are to be stored/retrieved in “CAPITAL.CSV” data file. It, consists of few records of Countries and their Capitals. He has written the, following code in python. As a programmer, you have to help him to, successfully execute the program., import csv, # Function to add a new record in CSV file, def _________(Country,Capital): # Statement-1, f=open("CAPITAL.CSV","__") # Statement-2, fwriter=csv.writer(f), fwriter.writerow([_____]) # Statement-3, f.close(), def ShowRec(): # Fn. to display all records from CSV file, with open("CAPITAL.CSV","r") as NF:, NewReader=csv._____ (NF) # Statement-4, for rec in NewReader:, if len(rec)!=0:, print(rec[0],rec[1]), AddNewRec("INDIA","NEW DELHI"), AddNewRec("CHINA","BEIJING"), ShowRec() # Statement-5, I. Choose the Name of the function in Statement-1., a) AddNewRec, KVSRO ERNAKULAM, , 171
Page 180 :
172, , b) Addnew, c) Addrec, d) AddNewRec(), II. Choose the file mode to be passed to add new records in Statement-2., a) w, b) r, c) w+, d) a, III. Identify the correct variables in Statement-3 to store data to the file., a) country,capital, b) Country,Capital, c) Coun,Cap, d) [Country,Capital], , IV. Choose the correct option for Statement-4 to read the data from a csv file., a) Reader(), b) reader(), c) read, d) reader, , V. Choose the output which will come after executing Statement-5., a) ‘INDIA NEW DELHI’, ‘CHINA BEIJING’, b) ‘CHINA’ ‘BEIJING’, c) INDIA NEW DELHI, KVSRO ERNAKULAM, , 172
Page 182 :
174, , I., , Name the module she should import in Line 1., a. CSV, b. csv, c. math, d. File, , II., , III., , IV., , In which mode, Rinsha should open the file to add data into the file., a. r, b. a, c. w, d. w+, Fill in the blank in Line 3 to read the data from a csv file., a. writer(), b. reader(), c. write(), d. read(), Fill in the blank in Line 4 to close the file., a. End(), b. Close(), c. close(), d. end(), , 26. Consider the following csv file and the code fragment associated with the, following csv file :, , import csv, f=open("c:\\stud.csv"), fobj=csv.reader(f), for k in fobj:, for j in k:, print(j, end=’’), break, f.close(), KVSRO ERNAKULAM, , 174
Page 183 :
175, , I.What will be the output printed by the above code?, a., b., c., d., , SLNO12345, SLNO, The entire content, Error, , II.What will be the output printed by the above code if the break is replaced with, continue?, a., b., c., d., , SLNO12345, SLNO, The entire content, Error, , III.What will occur if the file stud.csv is not existing in the mentioned path?, a., b., c., d., , It will create a new one, It will create an error, None of the above, It will cause a system reboot, , IV.Which statement in the above code will help to move to the next record?, a., b., c., d., , fobj.next(), next(fobj), fobj.move(), fobj.forward(), , 27.Sai Krishna has created the following csv file named item.csv:, , He has written the following program for managing the file. Help him to find the, answers for the following questions., import csv, csvfile=open("c:\\item.csv","r"), KVSRO ERNAKULAM, , 175
Page 184 :
176, , csvr=csv.reader(csvfile), head=next(csvfile), print(head)#Line1, for i in csvr:, print(i)#Line2, break, else:, print(i)#Line3, k=next(csvfile), print(k)#Line4, _______#Line5, I.What will be printed by Line1?, a. All the records, b. ITEMNO, NAME, PRICE, c.item.csv, d. None of the above, II. What will be printed by Line2?, a. 101,PENCIL,5, b. ITEMNO, NAME, PRICE, c.102,PEN,10, d. 103,NOTEBOOK,15, III. What will be printed by Line3?, a. 103,NOTEBOOK,15, b. Line 3 will not be executed, c. Line 3 will be executed , but nothing will be printed, d. 102,PEN,10, IV. What will be printed by Line4?, a. 101,PENCIL,5, b. ITEMNO, NAME, PRICE, c.102,PEN,10, d. 103,NOTEBOOK,15, , KVSRO ERNAKULAM, , 176
Page 185 :
177, , V., , What must be written in Line 5?, a. F.close(), b. f.close(), c. fobj.close(), d. csvfile.close(), , Assertion and Reasoning, 28.Assertion: All files must be closed after use., Reason :, A. Function close() is a compulsory part of the syntax, B. Data will be stored in secondary memory when we close the file, a. Only A is True, b. Only B is True, c. Both A and B are True, d. Both A and B are False, 29.Assertion: When we create a new file it is better to use the opening mode ‘x’, Reason:, A. It will avoid overwriting an existing file, B. It will prevent the risk of data loss, a. Only A is True, b. Only B is True, c. Both A and B are True, d. Both A and B are False, 30. Assertion:, The new record written in a file opened in a+ mode, will be added at the end., Reason :, A.The file pointer is at the end of the file if the file exists., B.The file will be created as a new file, a. Only A is True, b. Only B is True, c. Both A and B are True, d. Both A and B are False, KVSRO ERNAKULAM, , 177
Page 186 :
178, , ANSWERS, QNO, 1, 2, 3, 4, 5, , OPT, a, b, c, b, b, , QNO, 6, 7, 8, 9, 10, , OPT, b, b, c, a, b, , QNO, 11, 12, 13, 14, 15, , OPT, a, c, d, c, d, , QNO, 16, 17, 18, 19, 20, , OPT, d, a, a, c, d, , QNO, I, II, 21, III, IV, V, , OPT, b, a, c, d, b, , QNO, I, II, 22, III, IV, V, , OPT, d, c, b, b, d, , QNO, I, II, 23 III, IV, V, , OPT, c, c, b, a, c, , QNO, I, II, 24, III, IV, V, , OPT, d, d, b, D, b, , QNO, I, II, 25, III, IV, , OPT, b, b, b, c, , QNO, I, II, 26 III, IV, , OPT, b, c, b, b, , QNO, I, II, 27, III, IV, V, , OPT, b, a, b, c, b, , QNO, 28, 29, 30, , OPT, b, c, c, , KVSRO ERNAKULAM, , 178
Page 187 :
Sample Question Paper, Class: XII Session: 2021-22, Computer Science (Code 083), (Theory: Term-1), Maximum Marks: 35, , Time Allowed: 90 Minutes, , General Instructions:, The question paper is divided into 3 Sections - A, B and C., Section A, consist of 25 Questions (1-25). Attempt any 20 questions., Section B, consist of 24 Questions (26-49). Attempt any 20 questions., Section C, consist of 6 case study based Questions (50-55). Attempt any 5 questions., All questions carry equal marks., Q.N., Section-A, This section consists of 25 Questions (1 to 25). Attempt any 20 questions from this, section. Choose the best possible option., 1, , 2, , 3, , 4, , 5, , Find the invalid identifier from the following, a. none, b. address, c. Name, d. pass, Consider a declaration L = (1, 'Python', '3.14')., Which of the following represents the data type of L?, a. list, b. tuple, c. dictionary, d. string, Given a Tuple tup1= (10, 20, 30, 40, 50, 60, 70, 80, 90)., What will be the output of print (tup1 [3:7:2])?, a. (40,50,60,70,80), b. (40,50,60,70), c. [40,60], d. (40,60), Which of the following option is not correct?, a. if we try to read a text file that does not exist, an error occurs., b. if we try to read a text file that does not exist, the file gets created., c. if we try to write on a text file that does not exist, no error occurs., d. if we try to write on a text file that does not exist, the file gets, Created., Which of the following options can be used to read the first line of a text file Myfile.txt?, a. myfile = open('Myfile.txt'); myfile.read(), b. myfile = open('Myfile.txt','r'); myfile.read(n), c. myfile = open('Myfile.txt'); myfile.readline(), d. myfile = open('Myfile.txt'); myfile.readlines()
Page 188 :
6, , 7, , 8, , 9, , 10, , 11, , 12, , Assume that the position of the file pointer is at the beginning of 3rd line in a text file. Which, of the following option can be used to read all the remaining lines?, a. myfile.read(), b. myfile.read(n), c. myfile.readline(), d. myfile.readlines(), A text file student.txt is stored in the storage device. Identify the correct option out of the, following options to open the file in read mode., i. myfile = open('student.txt','rb'), ii. myfile = open('student.txt','w'), iii. myfile = open('student.txt','r'), iv. myfile = open('student.txt'), a. only i, b. both i and iv, c. both iii and iv, d. both i and iii, The return type of the input() function is, a. string, b. integer, c. list, d. tuple, Which of the following operator cannot be used with string data type?, a. +, b. in, c. *, d. /, Consider a tuple tup1 = (10, 15, 25, and 30). Identify the statement that will result in an, error., a. print(tup1[2]), b. tup1[2] = 20, c. print(min(tup1)), d. print(len(tup1)), Which of the following statement is incorrect in the context of binary files?, a. Information is stored in the same format in which the information is held in, memory., b. No character translation takes place, c. Every line ends with a new line character, d. pickle module is used for reading and writing, What is the significance of the tell() method?, a. tells the path of file, b. tells the current position of the file pointer within the file, c. tells the end position within the file, d. checks the existence of a file at the desired location
Page 189 :
13, , Which of the following statement is true?, a. pickling creates an object from a sequence of bytes, b. pickling is used for object serialization, c. pickling is used for object deserialization, d. pickling is used to manage all types of files in Python, , 14, , Syntax of seek function in Python is myfile.seek(offset, reference_point) where myfile is, the file object. What is the default value of reference_point?, a. 0, b. 1, c. 2, d. 3, Which of the following components are part of a function header in Python?, a. Function Name, b. Return Statement, c. Parameter List, d. Both a and c, Which of the following function header is correct?, a. def cal_si(p=100, r, t=2), b. def cal_si(p=100, r=8, t), c. def cal_si(p, r=8, t), d. def cal_si(p, r=8, t=2), Which of the following is the correct way to call a function?, a. my_func(), b. def my_func(), c. return my_func, d. call my_func(), Which of the following character acts as default delimiter in a csv file?, a. (colon) :, b. (hyphen) c. (comma) ,, d. (vertical line) |, Syntax for opening Student.csv file in write mode is, myfile = open("Student.csv","w",newline='')., , 15, , 16, , 17, , 18, , 19, , 20, , What is the importance of newline=''?, a. A newline gets added to the file, b. Empty string gets appended to the first line., c. Empty string gets appended to all lines., d. EOL translation is suppressed, What is the correct expansion of CSV files?, a. Comma Separable Values, b. Comma Separated Values, c. Comma Split Values, d. Comma Separation Values
Page 190 :
21, , 22, , 23, , 24, , Which of the following is not a function / method of csv module in Python?, a. read(), b. reader(), c. writer(), d. writerow(), Which one of the following is the default extension of a Python file?, a. .exe, b. .p++, c. .py, d. .p, Which of the following symbol is used in Python for single line comment?, a. /, b. /*, c. //, d. #, Which of the following statement opens a binary file record.bin in write mode and writes, data from a list lst1 = [1,2,3,4] on the binary file?, a. with open('record.bin','wb') as myfile:, pickle.dump(lst1,myfile), b. with open('record.bin','wb') as myfile:, pickle.dump(myfile,lst1), c. with open('record.bin','wb+') as myfile:, pickle.dump(myfile,lst1), , 25, , 26, , d. with open('record.bin','ab') as myfile:, pickle.dump(myfile,lst1), Which of these about a dictionary is false?, a) The values of a dictionary can be accessed using keys, b) The keys of a dictionary can be accessed using values, c) Dictionaries aren’t ordered, d) Dictionaries are mutable, Section-B, This section consists of 24 Questions (26 to 49). Attempt any 20 questions., What is the output of following code:, T=(100), print(T*2), a. Syntax error, b. (200,), c. 200, d. (100,100)
Page 191 :
27, , Suppose content of 'Myfile.txt' is:, Twinkle twinkle little star, How I wonder what you are, Up above the world so high, Like a diamond in the sky, , 28, , 29, , What will be the output of the following code?, myfile = open("Myfile.txt"), data = myfile.readlines(), print(len(data)), myfile.close(), a. 3, b. 4, c. 5, d. 6, Identify the output of the following Python statements., x = [[10.0, 11.0, 12.0],[13.0, 14.0, 15.0]], y = x[1][2], print(y), a. 12.0, b. 13.0, c. 14.0, d. 15.0, Identify the output of the following Python statements., x = 2, while x < 9:, print(x, end=''), x = x + 1, a. 12345678, b. 123456789, c. 2345678, d. 23456789, , 30, , Identify the output of the following Python statements., b = 1, for a in range(1, 10, 2):, b += a + 2, print(b), a. 31, b. 33, c. 36, d. 39
Page 192 :
31, , 32, , 33, , Identify the output of the following Python statements., lst1 = [10, 15, 20, 25, 30], lst1.insert( 3, 4), lst1.insert( 2, 3), print (lst1[-5]), a. 2, b. 3, c. 4, d. 20, Raghav is trying to write a tuple tup1 = (1,2,3,4,5) on a binary file test.bin. Consider the, following code written by him., import pickle, tup1 = (1,2,3,4,5), myfile = open("test.bin",'wb'), pickle._______ #Statement 1, myfile.close(), Identify the missing code in Statement 1., a. dump(myfile,tup1), b. dump(tup1, myfile), c. write(tup1,myfile), d. load(myfile,tup1), A binary file employee.dat has following data, Empno empname, Salary, 101, Anuj, 50000, 102, Arijita, 40000, 103, Hanika, 30000, 104, Firoz, 60000, 105, Vijaylakshmi 40000, def display(eno):, f=open("employee.dat","rb"), totSum=0, try:, while True:, R=pickle.load(f), if R[0]==eno:, __________, #Line1, totSum=totSum+R[2], except:, f.close(), print(totSum), When the above mentioned function, display (103) is executed, the output displayed is, 190000., Write appropriate jump statement from the following to obtain the above output.
Page 193 :
34, , 35, , 36, , 37, , a. jump, b. break, c. continue, d. return, What will be the output of the following Python code?, def add (num1, num2):, sum = num1 + num2, sum = add(20,30), print(sum), a. 50, b. 0, c. Null, d. None, Evaluate the following expression and identify the correct answer., 16 - (4 + 2) * 5 + 2**3 * 4, a. 54, b. 46, c. 18, d. 32, What will be the output of the following code?, def my_func(var1=100, var2=200):, var1+=10, var2 = var2 - 10, return var1+var2, print(my_func(50),my_func()), a. 100 200, b. 150 300, c. 250 75, d. 250 300, What will be the output of the following code?, value = 50, def display(N):, global value, value = 25, if N%7==0:, value = value + N, else:, value = value - N, print(value, end="#"), display(20), print(value), a. 50#50, b. 50#5, c. 50#30, d. 5#50#
Page 194 :
38, , 39, , 40, , 41, , What will be the output of the following code?, import random, List=["Delhi","Mumbai","Chennai","Kolkata"], for y in range(4):, x = random.randint(1,3), print(List[x],end="#"), a. Delhi#Mumbai#Chennai#Kolkata#, b. Mumbai#Chennai#Kolkata#Mumbai#, c. Mumbai# Mumbai #Mumbai # Delhi#, d. Mumbai# Mumbai #Chennai # Mumbai, What is the output of the following code snippet?, def ChangeVal(M,N):, for i in range(N):, if M[i]%5 == 0:, M[i]//=5, if M[i]%3 == 0:, M[i]//=3, L = [25,8,75,12], ChangeVal(L,4), for i in L:, print(i,end="#"), a) 5#8#15#4#, b) 5#8#5#4#, c) 5#8#15#14#, d) 5#18#15#4#, Suppose content of 'Myfile.txt' is, Humpty Dumpty sat on a wall, Humpty Dumpty had a great fall, All the king's horses and all the king's men, Couldn't put Humpty together again, What will be the output of the following code?, myfile = open("Myfile.txt"), record = myfile.read().split(), print(len(record)), myfile.close(), a. 24, b. 25, c. 26, d. 27, Find the output of the following code:, Name="PythoN3.1", R="", for x in range(len(Name)):, if Name[x].isupper():, R=R+Name[x].lower()
Page 195 :
elif Name[x].islower():, R=R+Name[x].upper(), elif Name[x].isdigit():, R=R+Name[x-1], else:, R=R+"#", print(R), , 42, , 43, , 44, , a. pYTHOn##@, b. pYTHOnN#@, c. pYTHOn#@, d. pYTHOnN@#, Suppose content of 'Myfile.txt' is, Honesty is the best policy., What will be the output of the following code?, myfile = open("Myfile.txt"), x = myfile.read(), print(len(x)), myfile.close(), a. 5, b. 25, c. 26, d. 27, Suppose content of 'Myfile.txt' is, Culture is the widening of the mind and of the spirit., What will be the output of the following code?, myfile = open("Myfile.txt"), x = myfile.read(), y = x.count('the'), print(y), myfile.close(), a. 2, b. 3, c. 4, d. 5, What will be the output of the following code?, x = 3, def myfunc():, global x, x+=2, print(x, end=' '), print(x, end=' '), myfunc(), print(x, end=' ')
Page 196 :
45, , 46, , a. 3 3 3, b. 3 4 5, c. 3 3 5, d. 3 5 5, Suppose content of 'Myfile.txt' is, Ek Bharat Shreshtha Bharat, What will be the output of the following code?, myfile = open("Myfile.txt"), vlist = list("aeiouAEIOU"), vc=0, x = myfile.read(), for y in x:, if(y in vlist):, vc+=1, print(vc), myfile.close(), a. 6, b. 7, c. 8, d. 9, Suppose content of 'Myfile.txt' is, Twinkle twinkle little star, How I wonder what you are, Up above the world so high, Like a diamond in the sky, Twinkle twinkle little star, , What will be the output of the following code?, myfile = open("Myfile.txt"), line_count = 0, data = myfile.readlines(), for line in data:, if line[0] == 'T':, line_count += 1, print(line_count), myfile.close(), a. 2, b. 3, c. 4, d. 5
Page 197 :
47, , Consider the following directory structure., , Suppose root directory (School) and present working directory are the same. What will, be the absolute path of the file Syllabus.jpg?, a. School/syllabus.jpg, b. School/Academics/syllabus.jpg, c. School/Academics/../syllabus.jpg, d. School/Examination/syllabus.jpg, 48, , Assume the content of text file, 'student.txt' is:, Arjun Kumar, Ismail Khan, Joseph B, Hanika Kiran, What will be the data type of data_rec?, myfile = open("Myfile.txt"), data_rec = myfile.readlines(), myfile.close(), a. string, b. list, c. tuple, d. dictionary, , 49, , What will be the output of the following code?, tup1 = (1,2,[1,2],3), tup1[2][1]=3.14, print(tup1), a. (1,2,[3.14,2],3), b. (1,2,[1,3.14],3), c. (1,2,[1,2],3.14), d. Error Message
Page 198 :
Section-C, Case Study based Questions, This section consists of 6 Questions (50 -55) Attempt any 5 questions., Rohit, a student of class 12, is learning CSV File Module in Python. During examination,, he has been assigned an incomplete python code (shown below) to create a CSV File, 'Student.csv' (content shown below). Help him in completing the code which creates the, desired CSV File., CSV File, 1,AKSHAY,XII,A, 2,ABHISHEK,XII,A, 3,ARVIND,XII,A, 4,RAVI,XII,A, 5,ASHISH,XII,A, Incomplete Code, import _____, fh = open(_____, _____, newline=''), stuwriter = csv._____, data = [ ], header = ['ROLL_NO', 'NAME', 'CLASS', 'SECTION'], data.append(header), for i in range(5):, roll_no = int(input("Enter Roll Number : ")), name = input("Enter Name : "), Class = input("Enter Class : "), section = input("Enter Section : "), rec = [ _____ ], data.append(_____), stuwriter. _____ (data), fh.close(), , #Statement-1, #Statement-2, #Statement-3, , #Statement-4, #Statement-5, #Statement-6, , 50, , Identify the suitable code for blank space in the line marked as Statement-1., , 51, , a) csv file, b) CSV, c) csv, d) cvs, Identify the missing code for blank space in line marked as Statement-2., , 52, , a) "Student.csv","wb", b) "Student.csv","w", c) "Student.csv","r", d) "Student.cvs","r", Choose the function name (with argument) that should be used in the blank space of line, marked as Statement-3., a) reader(fh), b) reader(MyFile), c) writer(fh), d) writer(MyFile)
Page 199 :
53, , Identify the suitable code for blank space in line marked as Statement-4., a) 'ROLL_NO', 'NAME', 'CLASS', 'SECTION', b) ROLL_NO, NAME, CLASS, SECTION, c) 'roll_no','name','Class','section', d) roll_no,name,Class,section, , 54, , Identify the suitable code for blank space in the line marked as Statement-5., a) data, b) record, c) rec, d) insert, , 55, , Choose the function name that should be used in the blank space of line marked as, Statement-6 to create the desired CSV File?, a) dump(), b) load(), c) writerows(), d) writerow()
Page 200 :
Marking Scheme, Class: XII Session: 2021-22, Computer Science (Code 083), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, , d. pass, b. tuple, d. (40,60), b. if we try to read a text file that does not exist, the file gets created., c. myfile = open('Myfile.txt'); myfile.readline(), d. myfile.readlines(), c. both iii and iv, a. string, d. /, b. tup1[2] = 20, c. Every line ends with a new line character, b. tells the current position of the file pointer within the file, b. pickling is used for object serialization, a. 0, d. Both a and c, d. def cal_si(p, r=8, t=2), a. my_func(), c. ,, d. EOL Translation is suppressed, , 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, , b. Comma Separated Values, a. read(), c. .py, d. #, a. with open('record.bin','wb') as myfile:, pickle.dump(lst1,myfile), b. The keys of a dictionary can be accessed using values, c. 200, b. 4, d. 15.0, c. 2345678, , 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, , c. 36, b. 3, b. dump(tup1, myfile), c. continue, d. None, c. 18, d. 250 300, b. 50#5, b. Mumbai#Chennai#Kolkata#Mumbai#, b. 5#8#5#4#, c. 26, b. pYTHOnN#@, d. 27
Page 201 :
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, , b. 3, d. 3 5 5, b. 7, a. 2, b. School/Academics/syllabus.jpg, b. list, b. (1,2,[1,3.14],3), c. csv, b. "Student.csv","w", c. writer(fh), d. roll_no,name,Class,section, c. rec, , 55, , c. writerows()
Page 202 :
CS21233, , KENDRIYA VIDYALAYA SANGATHAN,ERNAKULAM REGION, TERM I-PRACTICE TEST 2021-22, Class: XII, Computer Science – NEW- PYTHON (083), (Theory: Term-1 MARKING SCHEME), Maximum Marks: 35, , Time Allowed: 90 minutes, , General Instructions:, - A, B and C., -25). Attempt any 20 questions., -49). Attempt any 20 questions., ions (50-55). Attempt any 5 questions., All questions carry equal marks(0.77), , Q, No, ., , SECTION A, This section consists of 25 Questions (1 to 25). Attempt any 20 questions from this section., Choose the best possible option., , 1, , Identify the invalid identifier given below., a)_2017discount, , b) Profit, , c) Total-discount, , d) Totaldiscount, , Ans :c, , 2, , Multiline comments can be added using _____________ on each end of the comment., a)"' "'(triple quote), Ans: a, , 3, , b) # (Hash), , c) $ (dollar), , d) % (modulus), , The operators is and is not are _____________., a) Identity Operators, c) Membership Operators, , b) Comparison Operators, d) Unary Operators, , Ans : a, , 4, , Which of the following is/are valid declaration of a dictionary?, a) D = {'StuName': 'Alan', 'StuAge': 30, 'StuCity': 'Vizag'}, b) D = ['StuName': 'Alan', 'StuAge': 30, 'StuCity': 'Vizag'], c) D = ('StuName': 'Alan', 'StuAge': 30, 'StuCity': 'Vizag'), d) D = {'StuName'; 'Alan', 'StuAge': 30, 'StuCity': 'Vizag'}, Ans : a, , 5, , Given the lists L=[“K”, “V”, “S”, “E”, “R”,”K”] , write the output of print(L[1:4]), , Page 1 of 11
Page 203 :
a)['K', 'V', 'S'], c) ['K', 'V', 'S', 'E'], , b) ['V', 'S', 'E'], d) ['V', 'S', 'E', 'R'], , Ans : b, , 6, , A local variable in Python is a variable that is,, a. Defined inside every function, c. Accessible from within the function, , b. Local to the given program, d. All of these, , Ans : d, , 7, , Which keyword is used to define a function?, a)Fun, , b)Define, , c)def, , d)function, , Ans : c, , 8, , To import specific functions in a program from a module, ……… statement can be used., a)with, , b)from, , c)import, , d)open, , Ans : b, , 9, , Multiple values from a function in Python are returned through the following:, a)List, , b)String, , c)Tuple, , d)All of these, , Ans : c, , 10, , If return statement is not used inside the function, the function will return:, a) None, , b) 0, , c) Null, , d) Arbitary value, , Ans : a, , 11, , Which of the following commands can be used to read “n” number of characters from a file, using the file object <file>?, a) file.read(n), , b) n = file.read(), , c). file.readline(n), , d) file.readlines(), , Ans : a, , 12, , CSV module allows to write multiple rows using ____________ function., a. writerows( ) b. writerow( ) c. writer( ) d. None of the above, Ans : a, , 13, , By default a file in python is opened in …………………..mode., a)read, b)write, c)read and write, , d)binary, , Ans : a, , 14, , What does the <readlines()> method returns?, a) string, , b) a list of strings, , c) list of single characters, , d) list of integers, , Ans : b, , 15, , Which of the following statements are true?, a) When you open a file for reading, if the file does not exist, an error occurs, b) When you open a file for writing, if the file does not exist, a new file is created, c) When you open a file for writing, if the file exists, the existing file is overwritten with the, new file, d) All of the mentioned, Ans : d, Page 2 of 11
Page 204 :
16, , Choose the correct output of the following Python Statement:, print(math.ceil(81.3)), a)80, , b)81, , c)82, , d)81.3, , Ans : c, , 17 The file paths from the topmost level of the directory structure is known as, a)File path, , b)Absolute path, , c)Relative Path, , d)None, , Ans : b, , 18 Consider a file named rome.txt, then the statement used to open a file for reading,, , a. infile = open("c:\rome.txt", "r"), b. infile = open("c:\\rome.txt", "r"), c. infile = open(file = "c:\rome.txt", "r"), d. infile = open(file = "c:\\rome.txt", "r"), Ans : b, 19 Which of the following results in a Syntax Error ?, , a) ‘”Once upon a time…”, she said.’, , b) “He said, ‘Yes!'”, , c) ‘3\’, , d) ”’That’s okay”’, , Ans : c, 20, , Evaluate the expression and choose the correct answer: 9-5//2+7**2-1, a)53, , b)51, , c)55, , d)57, , Ans : c, 21, , What will be the output of the following Python expression?, print(round(4.576)), a)4, , b)4.6, , c)5, , d)4.5, , Ans : c, , 22, , Consider the following function headers. Identify the correct statement: a) def correct(a=1,b=2,c):, b) def correct(a=1,b,c=3):, c) def correct(a=1,b=2,c=3):, d) def correct(a=1,b,c):, Ans : c, 23, , Which one of the following is the default extension of a Python file?, a. .exe, b. .p+, c. .py, d. .python, Ans : c, , 24, , Which of the following character acts as default delimiter in a csv file?, a. (colon) :, Page 3 of 11
Page 205 :
b. (hyphen) c. (comma) ,, d. (vertical line) |, Ans : c, , 25, , ……………………are the values provided in function call/invoke functions., a.Functions, b.Arguments, c.Preprocessors, d.Models, Ans : B, , SECTION B, , This section consists of 24 Questions (26 to 49). Attempt any 20 questions., 26, , What possible outputs(s) are expected to be displayed on screen at the time of execution of the, program from the following code?, import random, x=3, N = random, randint (1, x), for i in range (N):, print(i, ‘#’, i + i), a) 0#0, 1#2, , b) 1#2, 2#2, , c) 2#3, 1#2, , d) 3#4, 2#3, , Ans : a, , 27, , Choose the correct output of the following Python code:, def fsum():, n = 60, i=6, s=0, while i<n:, s+= i, i+= 10, print("sum", s), fsum(), a)184, , b)186, , c)130, , d)84, , Ans : b, , 28, , What will be the output generated by the following snippet?, def fun1(m=8,n=10):, global x, x=4, y=6, print (m+n-x), def fun2():, x=5, return x, print(fun2()), Page 4 of 11
Page 206 :
a,b=5,10, x=20, fun1(b), print(x), a)16, 20, 4, , b) 5, 16, 4, , c) 20, 16, 4, , d) 20, 16, 20, , Ans : b, 29, What will be the output generated by the following snippet?, a = [5, 10, 15, 20, 25], k=1, i = a[1] + 1, j = a[2] +1, m = a[k+1], print (i, j, m), a) 11 15 16, c) 11 15 15, , b) 11 16 15, d) 16 11 15, , Ans : b, , 30, , What will be the output of following code:, def Alter(x, y = 10, z=20):, sum1=x+y+z, print(sum1), Alter(10,20,30), Alter(20,30), Alter(100), , a)50, , b)60, , c)60, , d)50, , 60, , 70, , 50, , 70, , 120, , 130, , 120, , 120, , Ans : b, , 31, , Find the correct code after removing the errors: def SI(p,t=2,r):, return (p*r*t)/100, a)def SI(p, ,r):, return(p*r*t)/100, b) Def SI(p,t,r):, return(p*r*t)/100, c)def SI(p,r,t=2):, , Page 5 of 11
Page 207 :
return(p*r*t)/100, d) def SI(t=2,p,r):, return(p*r*t)/100, Ans : c, , 32, , Given the S = “KENDRIYA VIDYALAYA ” , write the output of print(S[-1:-10:-2]), a)KNRY, , b) AYALA, , c) AAADV, , d) YLYI, , Ans : c, , 33, , Complete the given python code to create and add the given content to a binary file., import pickle, listvalues=[1,"Geetika",'F', 26], fileobject=open("mybinary.dat", "wb"), pickle . ……………………..(listvalues,……………………..), fileobject.close(), a)load ,fileobject, , b)open, fileobject c)dump, fileobject, , #line1, , d)fileobject, dump, , Ans : c, , 34, , Find and write the output of the following Python code:, def fun(s):, k=len(s), m=" ", for i in range(0,k):, if(s[i].isupper()):, m=m+s[i].lower(), elif s[i].isalpha():, m=m+s[i].upper(), else:, m=m+'bb', print(m), fun('school2@com'), a) SCHOOLbbbbCOM, , b) SCHOOL@@@COM, , c) Shool2bbbbcom, , d) Shoolbbbbcom, , Ans : c, , 35, , Suppose content of 'Myfile.txt' is, We may be young or old,, But we must be bold,, Against the enemy untold., If you have to go out, think twice,, Wear your mask, be wise., After coming home, sanitise,, And wash your hands thrice., Page 6 of 11
Page 208 :
What will be the output of the following code?, myfile = open("Myfile.txt"), line_count = 0, data = myfile.readlines(), for line in data:, if line[0] == 'W':, line_count += 1, print(line_count), myfile.close(), a) 1, , b) 2, , c) 3, , d), , 4, , Ans : b, , 36, , What will be the output of the following code?, tup1 = (1,2,[1,2],3), tup1[2][1]=3.14, print(tup1), a. (1,2,[3.14,2],3), b. (1,2,[1,3.14],3), c. (1,2,[1,2],3.14), d. Error Message, Ans : b, , 37, , Hari is trying to write a tuple tup1 = (1,2,3,4,5) on a binary file test.bin. Consider the following, code written by him., import pickle, tup1 = (1,2,3,4,5), myfile = open("test.bin",'wb'), pickle._______ #Statement 1, myfile.close(), Identify the missing code in Statement 1., a. dump(myfile,tup1), b. dump(tup1, myfile), c. write(tup1,myfile), d. load(myfile,tup1), Ans : b, , 38, , What will be the output of the following code, str1=”I love Python”, strlen=len(str1)+5, print(strlen), a)18, , b), , 19, , c), , 13, , d) 15, Page 7 of 11
Page 209 :
Ans : a, , 39, , What is the output of the program given below:, x=50, def func(x):, x=2, func(x), print(‘x is now’,x), a) x is now 50, b) x is now 100, , b) x is now 2, d) Error, , Ans : a, , 40, , What is the output of the following statement ?, print("xyyzxyzxzxyy".count('yy,1')), a)2, , b)0, , c)1, , d)error, , Ans : b, , 41, , Assertion - close () method closes the file and frees the memory space acquired by that file., Reason - one should always close their files, in some cases, due to buffering, changes made to a, file may not show until the file is closed., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is not the correct explanation of A., C - A is true but R is false., D - A is false but R is true., Ans : b, , 41, , What is the output of below program?, def say(message, times = 1):, print(message * times), say('Hello'), say('World', 5), a) Hello, WorldWorldWorldWorldWorld, b) Hello World 5, c) Hello World,World,World,World,World, d) Hello HelloHelloHelloHelloHello, Ans : a, , 43, , Which statement will read 5 characters from a file(file object 'f')?, a)f.read(), b) f.read(5), Page 8 of 11
Page 210 :
c)f.reads(5), d)f.readline(5), Ans : b, , 44, , Which function is used to force transfer of data from buffer to file?, a)save(), b)tell(), c)seek(), d)flush(), Ans : d, , 45, , What is the output of the below program?, def printMax(a, b):, if a > b:, print(a, 'is maximum'), elif a == b:, print(a, 'is equal to', b), else:, print(b, 'is maximum'), printMax(3, 4), , a) 3, b) 4, c) 4 is maximum, d) None of the mentioned, Ans : c, , 46, , Incorrect Indentation results in _____________., a. IndentationError, b. NameError, c. TypeError, d. SyntaxError, Ans : d, , 47, , Find the output of the following code snippet., for i in range(10):, if i == 5:, break, else:, print(i), a. 0 1 2 3 4, b. 0 1 2 3 4 5, c. 0 1 2 3, Page 9 of 11
Page 211 :
d. 1 2 3 4 5, Ans : a, , 48, , The syntax to write to a CSV file is, a. csv.DictWriter(filehandler), b. csv.reader(filehandler), c. csv.writer(filehandler), d. csv.write(filehandler), Ans : c, , 49, , What will be the output of following code?, def check():, global num, num=1000, print(num), num=100, print(num), check(), print(num), a)100, 100, 1000, , b)100, 1000, 1000, , c)1000, 1000, 1000, , d)1000, 100, 1000, , Ans : b, , SECTION C, Case Study based Questions, This section consists of 6 Questions (50 -55) Attempt any 5 questions., Ankit of class 12 is writing a program to create a CSV file “BoardDetails.csv” which will, contain BoardRollNo, StuName, DateOfBirth for some entries. He has written the following, code. As a programmer, help him to successfully execute the given task., INCOMPLETE CODE, import _____________, #Line 1, def addCsvFile(BoardRollNo,StuName, DateOfBirth):, f=open('________________,'a',newline=''), #Line 2, x = csv.writer(f), x . ………………..([BoardRollNo,StuName, DateOfBirth]), #Line 3, f.close(), def readCsvFile():, f=open('BoardDetails.csv','__'), y = csv._________, for row in y:, if (int(row[0])>9107750):, print(row[0],row[1]), , #Line 4, #Line 5, , Page 10 of 11
