Python ProgrammingPython Programming

Python While Loop

In this tutorial you'll learn how to repeat a series of actions using while loop in Python.

A condition-controlled loop causes a block of code to repeat as long as a condition is true. The while statement is used to write condition-controlled loop in Python.


The while Loop

The while loop checks whether the expression that follows it evaluates to true or not. It keeps executing until the expression returns true.

Example
This while loop executes 10 times unless the condition num is less than or equal to 10 returns false.
num = 1
 
while num <= 10:
    print("5 X ", num, " = ", 5 * num)
    num = num + 1
 
Output
5 X  1  =  5
5 X  2  =  10
5 X  3  =  15
5 X  4  =  20
5 X  5  =  25
5 X  6  =  30
5 X  7  =  35
5 X  8  =  40
5 X  9  =  45
5 X  10  =  50

The break Statement

The break statement is used to terminate the execution of loop even if the while condition is true.

Example
Exit the loop when num is 5:
num = 1
 
while num <= 10:
    print("5 X ", num, " = ", 5 * num)
    if num == 5:
        break
    num = num + 1
 
Output
5 X  1  =  5
5 X  2  =  10
5 X  3  =  15
5 X  4  =  20
5 X  5  =  25

The continue Statement

The continue statement is used to skip or stop the remaining iteration of loop and to shift the control back to the beginning of the loop.

Example
Continue to the next iteration if num is 5:
num = 0
 
while num <= 10:
    num = num + 1
    if num > 5:
        continue
    print("5 X ", num, " = ", 5 * num)
 
Output
5 X  1  =  5
5 X  2  =  10
5 X  3  =  15
5 X  4  =  20
5 X  5  =  25