Page 2 :
for more updates visit: www.python4csip.com, , Python Character Set, Is a set of valid characters that python can recognize. A, character represent letters, digits or any symbol. Python, support UNICODE encoding standard. Following are the, Python character set, Letters, : A-Z, a-z, Digits, : 0-9, Special symbols :space +-*/()~`!@#$%^ & [{, ]};:‟”,<.>/?, White spaces, : Blank space, Enter, Tab, Other character : python can process all ASCII and, UNICODE as a part of data or literal, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 5 :
for more updates visit: www.python4csip.com, , IDENTIFIERS, Are the names given to different parts of program like variables,, objects, classes, functions etc., Identifier forming rules of Python are :, , , , , , , , , , Is an arbitrarily long sequence of letters and digits, The first character must be letter or underscore, Upper and lower case are different, The digits 0-9 are allowed except for first character, It must not be a keyword, No special characters are allowed other than underscore is allowed., Space not allowed, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 9 :
for more updates visit: www.python4csip.com, , Non-Graphic (Escape) characters, , , They are the special characters which cannot be, type directly from keyboard like backspace, tabs,, enter etc. When the characters are typed they, perform some action. These are represented by, escape characters. Escape characters are always, begins from backslash(\) character., , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 11 :
for more updates visit: www.python4csip.com, , String type in Python, , , Python allows you to have two string types:, Single, , Line Strings, , The, , string we create using single or double quotes are, normally single-line string i.e. they must terminate in one line., For e.g if you type as, , , , Name="KV and press enter, Python we show you an error “EOL while scanning string literal”, , The, , reason is quite clear, Python by default creates single-line, string with both single quotes and it must terminate in the same, line by quotes, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 14 :
for more updates visit: www.python4csip.com, , Size of String, , , Python determines the size of string as the count of characters in the string., For example size of string “xyz” is 3 and of “welcome” is 7. But if your, string literal has an escape sequence contained in it then make sure to count, the escape sequence as one character. For e.g., String, , Size, , „\\‟, , 1, , „abc‟, , 3, , „\ab‟, , 2, , “Meera\‟s Toy”, , 11, , “Vicky‟s”, , 7, , , , You can check these size using len() function of Python. For example, , , , >>>len(„abc‟) and press enter, it will show the size as 3, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 16 :
for more updates visit: www.python4csip.com, , Numeric Literals, , , The numeric literals in Python can belong to any of, the following numerical types:, 1) Integer Literals: it contain at least one digit and must, not contain decimal point. It may contain (+) or (-) sign., Types of Integer Literals:, a) Decimal : 1234, -50, +100, b) Octal : it starts from symbol 0o (zero followed by, letter ‘o’), For, , e.g. 0o10 represent decimal 8, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 18 :
for more updates visit: www.python4csip.com, , Numeric Literals, , , , , 2) Floating point Literals: also known as real, literals. Real literals are numbers having fractional, parts. It is represented in two forms Fractional Form, or Exponent Form, Fractional Form: it is signed or unsigned with decimal point, , , , , For e.g. 12.0, -15.86, 0.5, 10. (will represent 10.0), , Exponent Part: it consists of two parts “Mantissa” and, “Exponent”., , , For e.g. 10.5 can be represented as 0.105 x 102 = 0.105E02 where, 0.105 is mantissa and 02 (after letter E) is exponent, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 19 :
for more updates visit: www.python4csip.com, , Points to remember, , , , , Numeric values with commas are not considered int or float value, rather Python, treats them as tuple. Tuple in a python is a collection of values or sequence of values., (will be discussed later on), You can check the type of literal using type() function. For e.g., >>> a=100, >>> type(a), <class 'int'>, >>> b=10.5, >>> type(b), , <class 'float'>, >>> name="hello“, >>> type(name), , <class 'str'>, >>> a=100,50,600, >>> type(a), VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR, , <class 'tuple'>
Page 22 :
for more updates visit: www.python4csip.com, , Complex Numbers, Complex: Complex number in python is made up of two floating point values,, one each for real and imaginary part. For accessing different parts of, variable (object) x; we will use x.real and x.image. Imaginary part of the, number is represented by “j” instead of “I”, so 1+0j denotes zero imaginary., part., Example, >>> x = 1+0j, >>> print x.real,x.imag, 1.0 0.0, Example, >>> y = 9-5j, >>> print y.real, y.imag, 9.0 -5.0, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 23 :
for more updates visit: www.python4csip.com, , Conversion from one type to another, Python allows converting value of one data type to another data, type. If it is done by the programmer then it will be known as type, conversion or type casting and if it is done by compiler automatically, then it will be known as implicit type conversion., Example of Implicit type conversion, >>> x = 100, >>> type(x), <type 'int'>, >>> y = 12.5, >>> type(y), <type 'float'>, >>> x=y, >>> type(x), <type 'float'>, # Here x is automatically converted to float, , , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 25 :
for more updates visit: www.python4csip.com, , Simple Input and Output, , , , , In python we can take input from user using the built-in function, input()., Syntax, , variable = input(<message to display>), Note: value taken by input() function will always be of String type, so by, default you will not be able to perform any arithmetic operation on variable., >>> marks=input("Enter your marks "), Enter your marks 100, >>> type(marks), <class 'str'>, Here you can see even we are entering value 100 but it will be treated as, string and will not allow any arithmetic operation, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 27 :
for more updates visit: www.python4csip.com, , Reading / Input of Numbers, , , Now we are aware that input() function value will, always be of string type, but what to do if we want, number to be entered. The solution to this problem is, to convert values of input() to numeric type using int(), or float() function., , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 28 :
for more updates visit: www.python4csip.com, , Possible chances of error while taking, input as numbers, 1., , Entering float value while converting to int, , >>> num1=int(input("Enter marks ")), Enter marks 100.5, Traceback (most recent call last):, File "<stdin>", line 1, in <module>, ValueError: invalid literal for int() with base 10: '100.5‘, 2. Entering of values in words rather than numeric, >>> age=int(input("What is your age ")), What is your age Eighteen, Traceback (most recent call last):, File "<stdin>", line 1, in <module>, ValueError: invalid literal for int() with base 10: Eighteen', VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 29 :
for more updates visit: www.python4csip.com, , Possible chances of error while taking, input as numbers, 3. While input for float value must be compatible. For e.g., Example 1, >>> percentage=float(input("Enter percentage ")), Enter percentage 12.5.6, Traceback (most recent call last):, File "<stdin>", line 1, in <module>, ValueError: could not convert string to float: '12.5.6', , Example 2, >>> percentage=float(input("Enter percentage ")), Enter percentage 100 percent, Traceback (most recent call last):, File "<stdin>", line 1, in <module>, ValueError: could not convert string to float: „100 percent', VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 31 :
for more updates visit: www.python4csip.com, , Let us write few programs, , , , , , , , , , , , WAP to enter length and breadth and calculate area, of rectangle, WAP to enter radius of circle and calculate area of, circle, WAP to enter Name, marks of 5 subject and calculate, total & percentage of student, WAP to enter distance in feet and convert it into inches, WAP to enter value of temperature in Fahrenheit and, convert it into Celsius., WAP to enter radius and height of cylinder and, calculate volume of cylinder., VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 32 :
for more updates visit: www.python4csip.com, , Operators, , , are symbol that perform specific operation when, applied on variables. Take a look at the expression:, (Operator), 10 + 25, , (Operands), , Above statement is an expression (combination, of operator and operands), i.e. operator operates on operand. some operator requires two, operand and some requires only one operand to operate, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 36 :
for more updates visit: www.python4csip.com, , Bitwise operator, Operator, , Purpose, , Action, , &, , Bitwise AND, , Return 1 if both, inputs are 1, , ^, , Bitwise XOR, , Return 1, if the, number of 1 in, input is in odd, , |, , Bitwise OR, , Return 1 if any, input is 1, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR, , Bitwise operator works, on the binary value of, number not on the actual, value. For example if 5, is passed to these, operator it will work on, 101 not on 5. Binary of, 5 is 101, and return the, result in decimal not in, binary.
Page 37 :
for more updates visit: www.python4csip.com, , Example, , Guess the output with, | and ^ ?, , Binary of 12 is 1100 and 7 is 0111, so applying &, 1100, 0111, ------0100 Which is equal to decimal value 4, , Let us see one practical example, To check whether entered number is divisible of 2 (or in, a power of 2 or not) like 2, 4, 8, 16, 32 and so on, To check this, no need of loop, simply find the bitwise & of n and n-1, if the result is 0 it, means it is in power of 2 otherwise not, , Here we can see 0,, it means 32 is in, power of 2, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR, , Later on by using „if‟ we can print, meaningful message, , Here we can see, 16, it means 24 is, not in power of 2
Page 44 :
for more updates visit: www.python4csip.com, , Barebones of Python Program, , , Indentation, , Statements, , , , It means basic structure of a Python program, Take a look of following code:, , #This program shows a program‟s component, # Definition of function SeeYou() follows, def SeeYou():, print(“This is my function”), #Main program, Function, A=10, B=A+20, C=A+B, Expressions, if(C>=100), #checking condition, print(“Value is equals or more than 100”), else:, print(“Value is less than 100”), SeeYou(), #Calling Function, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR, , Comments, , Inline Comment, , Block
Page 45 :
for more updates visit: www.python4csip.com, , Expression, , , An expression is any legal combination of symbols that, represents a value. An expression is generally a, combination of operators and operands, Example:, expression of values only, 20, 3.14, Expression that produce a value when evaluated, A+10, Salary * 10 / 100, VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 46 :
for more updates visit: www.python4csip.com, , Statement, It is a programming instruction that does something i.e., some action takes place., Example, print(“Welcome to python”), The above statement call print function, When an expression is evaluated a statement is executed, i.e. some action takes place., a=100, b = b + 20, , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 47 :
for more updates visit: www.python4csip.com, , Comments, Comments are additional information written in a, program which is not executed by interpreter i.e., ignored by Interpreter. Comment contains information, regarding statements used, program flow, etc., Comments in Python begins from #, Python supports 3 ways to enter comments:, 1., Full line comment, 2., Inline comment, 3., Multiline comment, , , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 51 :
for more updates visit: www.python4csip.com, , Block and Indentation, Group of statement is known as block like function,, conditions or loop etc., For e.g., def area():, a = 10, b=5, c=a*b, Indentation means extra space before writing any, statement. Generally four space together marks the next, indent level., , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 52 :
for more updates visit: www.python4csip.com, , Variables, , , , , , , Variables are named temporary location used to store, values which can be further used in calculations, printing, result etc. Every variable must have its own Identity, type, and value. Variable in python is created by simply, assigning value of desired type to them., For e.g, Num = 100, Name=“James”, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 53 :
for more updates visit: www.python4csip.com, , Variables, Note: Python variables are not storage containers like other, programming language. Let us analyze by example., In C++, if we declare a variable radius:, radius = 100, [suppose memory address is 41260], Now we again assign new value to radius, radius = 500, Now the memory address will be still same only value, will change, , , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 54 :
for more updates visit: www.python4csip.com, , Variables, Now let us take example of Python:, radius = 100, [memory address 3568], , , , radius = 700, , [memory address 8546], , Now you can see that In python, each time you assign new, value to variable it will not use the same memory address, and new memory will be assigned to variable. In python the, location they refer to changes every time their value, change.(This rule is not for all types of variables), VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 57 :
for more updates visit: www.python4csip.com, , Multiple Assignments, Python is very versatile with assignments. Let‟s see in how different ways, we can use assignment in Python:, 1. Assigning same value to multiple variable, a = b = c = 50, 2. Assigning multiple values to multiple variable, a,b,c = 11,22,33, , , , Note: While assigning values through multiple assignment, remember that, Python first evaluates the RHS and then assigns them to LHS, Examples:, , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 58 :
for more updates visit: www.python4csip.com, , Multiple Assignments, x,y,z = 10,20,30, z,y,x = x+1,z+10,y-10, print(x,y,z), Output will be, 10 40 11, , #Statement 1, #Statement 2, , Now guess the output of following code fragment, x,y = 7,9, y,z = x-2, x+10, print(x,y,z), VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 59 :
for more updates visit: www.python4csip.com, , Multiple Assignments, Let us take another example, , y, y = 10, 20, In above code first it will assign 10 to y and again it assign 20, to y, so if you print the value of y it will print 20, Now guess the output of following code, x, x = 100,200, y,y = x + 100, x +200, print(x,y), VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 60 :
for more updates visit: www.python4csip.com, , Variable definition, Variable in python is create when you assign value to it, i.e. a variable is not create in memory until some value is, assigned to it., Let us take as example(if we execute the following code), print(x), Python will show an error „x‟ not defined, So to correct the above code:, x=0, print(x), #now it will show no error, , , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 61 :
for more updates visit: www.python4csip.com, , Dynamic Typing, , , , , , , In Python, a variable declared as numeric type can be, further used to store string type or another., Dynamic typing means a variable pointing to a value of, certain type can be made to point to value/object of, different type., Lets us understand with example, x = 100, # numeric type, print(x), x=“KVians”, # now x point to string type, print(x), VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 63 :
for more updates visit: www.python4csip.com, , Caution with Dynamic Typing, Always ensure correct operation during dynamic typing., If types are not used correctly Python may raise an, error., Take an example, x = 100, y=0, y=x/2, print(y), x='Exam', y = x / 2 # Error, you cannot divide string, , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 66 :
for more updates visit: www.python4csip.com, , Output through print(), Example 3, r = int(input("Enter Radius ")), print("Area of circle is ",3.14*r*r), , Note: from the Example 2 and Example 3 we can, observe that while printing numeric value print() convert, it into equivalent string and print it. In case of expression, (Example 3) it first evaluate it and then convert the result, to string before printing., VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR
Page 77 :
for more updates visit: www.python4csip.com, , Just a minute…, , , WAP to obtain temperature in Celsius and convert it into, Fahrenheit. F = 9*C/5 + 32, , What will be the output of following code:, x, y = 6,8, x,y = y, x+2, print(x,y), What will be the output of following code:, x,y = 7,2, x,y,x = x+4, y+6, x+100, print(x,y), , , , VINOD KUMAR VERMA, PGT(CS), KV OEF KANPUR &, SACHIN BHARDWAJ, PGT(CS), KV NO.1 TEZPUR