Class 12 : Review Of Python Basics

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Class 12 : Python

Python Basics
Data Types
String
List
Tuple
Dictionary
Flow of Execution
Mutable and Immutable Types
Type Casting

Class 12 : Python Revision MCQs

Revision Tour MCQs

Class 12 | Revision Tour 10

By: Archana Shukla and Rajesh Shukla

Flow of execution

The way in which the statements are executed defines the flow of execution in a python program. It is categorized in the following types:

Sequential statements

In this type the statements are executed one after the other from the very first statement to the last statement.

Example 1 : program to compute area of a circle

r=int(input('enter the radius of a circle: '))
area=3.14*r*r
print('area of a circle is : ',area)

Output
enter the radius of a circle: 2
area of a circle is : 12.56
>>>

Selection / conditional statements

These type of statements are executed on the basis of the given condition whether the condition is true or false. If statement is used for decision making or selection in programming.

Syntax:
if (test expression):
       statement(s)

Here, the program evaluates the test expression and will execute statement(s) only if the test expression is True.

Example

age=int(input('enter your age :'))
if age>=18:
    print('eligible for voting')

Output
enter your age :20
eligible for voting
>>>

Python If…else statement

The if..else statement evaluates test expression and will execute body of if only when test condition is True. If the condition is False, body of else is executed. Indentation is used to separate the blocks.

Example

age=int(input('enter your age :'))
if age>=18:
    print('eligible for voting')
else:
    print('not eligible')

Output
enter your age :12
not eligible
>>>

Python if…elif…else

Syntax

if (test expression):
       Body of if
elif (test expression):
       Body of life
 else:
       Body of else

Here else is optional. Number of elif depends on number of conditions

Example: To print the name of the week day.

 d=int(input("Enter days no (1..7)"))
if(d==1):
    print("Sun")
elif(d==2):
    print("Mon")
elif(d==3):
    print("Tue")
elif(d==4):
    print("Wed")
elif(d==5):
    print("Thur")
elif(d==6):
    print("Fri")
elif(d==7):
    print("Sat")
else:
    print("Invalid day number")

Nested if … else statement

It allows us to check for multiple test expressions and execute different codes for more than two conditions.

Syntax

if (test expression):
      Body of if
else:
      if (test expression):
              Body of if
      else:
              Body of else

Example: To check whether the number is +ve or -ve or 0.

a=int(input("Enter any no "))
if(a==0):
    print("number is zero")
else:
    if(a>0):
        print("number is +ve")
    else:
        print("number is -ve")

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