Conditional statements in Python

05 min read

Program 5:

Loops in Python:

Note: In python we use indentation to mark the length of the loops. In other words, we use specific gaps/ spaces to mark the region of the loop. The syntax for the conditional statements are listed below.

 

if-else statement syntax

 if test_expression:
                Body starts
else:
                Body ends

 

while loop syntax

while test_expression:
                Body of while

 

for loop syntax

 for value in sequence:
                Body of for

 

 if-else statement:

if is a conditional statement which executes only if the condition declared is True. For example,

 x=4                                                                          #declared a variable with an integer value of 4.
if x > 2:                                                                   # remember to give a colan, check if condition is true
                print(‘big number’)                         # indentation (gap) refers to the body of the loop.
else:
                print(‘small number’)

 

In the above code, if the condition x>2 is True: then all the lines in the indent followed by the ‘if’ conditional statement are executed

Let us consider another example program for ‘for loop’

S=[1,2,3,4,5]                           #declare a list of numbers
for I in S:                                    # for every I in the list S
       if i>2:                                     # check if the current value of I is greater than 2
              print(‘big’)                    # if condition true, print ‘big’
       else:
              print(‘small’)                #if above condition is false, print ‘small’
print(‘all numbers are over’)        # observe indentation. The print statement is in line with for statement, stating that it is no more in the ‘for loop’.

 

Output:

Small
Small
Big
Big
Big
All numbers are over

 

The use of if-elif-else  to implement multiple conditions in a single program:

 For example,

x=4
if x<2:
                print(‘small’)
elif x<10:
                print(‘medium’)
else:
                print(‘large’)
print(‘all numbers over’)
output:

medium
all numbers over

 

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