Python If...Else

Along with the if statement,else keyword can also be optionally used.

It provides an alternate block of statements to be executed if the Boolean expression (in if statement) is not true.

This flowchart shows how else block is used.

If the expr is True, block of stmt 1,2,3 is executed then the default flow continues with stmt7. However, the If expr is False, block stmt 4,5,6 runs then the default flow continues.

   if expr==True:
       stmt1
       stmt2
       stmt3
    else:
       stmt4
       stmt5
       stmt6
    Stmt7    
    
   
                         
             

Python implementation of the above flowchart is as follows:

   age=int(input("Enter the age : "))
    if age>=18:
       print("Eligible to Vote")
    else:
       print("Not eligible to Vote")   
       
        Output
        Enter the age :25
        Eligible to Vote
                         
             

Elif

The elif keyword is a way of saying "if the previous condition is not true,then try this condition".

  a=30
    b=90
    if a>b:
       print("a is greater")
    elif a==b:
        print("Both are equal")
    else:
        print("b is greater")
        
        
        Output
       b is greater