Page 117 - 2622_Delhi Police Public School_C-8

The syntax of while statement is given below:

while (test expression): Hintbot
Statements
To generate a series in reverse
increment/decrement expression order: "start" value must be
greater than "stop" value and
"step size" should be negative.

Program 6: To print first 5 natural numbers using while loop.

Program6.py Output

File Edit Format Run Options Window Help 1
2
i=1
3
while i<6:
4
print(i)
5
i+=1

The Infinite Loop

If the condition given in a loop never becomes false, then the loop will never terminate and run
indefinitely. This type of loop is called an infinite loop.
Example:

while(1):
print(“Hello”)
Output: Hello will be printed infinite times.

To come out of the infinite loop, we can either close the program window. This will break the running
of the program.

The while Loop using else Statement

Python enables the use of else statement with the while loop. The else block is executed when the
condition given in the while statement becomes false.
Program 7: To demonstrate the use of while loop with else statement.

Program7.py Output

File Edit Format Run Options Window Help 1
2
i=1
3
while i<= 5:
4
print(i)
5
i=i+1
The while loop ends here
else:
print('The while loop ends here')

Loops in Python 115