While loop

A while loop repeats code until the condition is met. Unlike for loops, the number of iterations in it may be unknown.  A while loop always consists of a condition and a block of code.

A while loop ends if and only if the condition is true, in contrast to a for loop that always has a finite countable number of steps.

while loop

Related course: Complete Python Bootcamp: Go from zero to hero in Python


The while loop below defines the condition (x < 10) and repeats the instructions until that condition is true. Type this code:

Executes the code below until the condition x < 10 is met.   Unlike a for loop, the iterator i is increased in the loop.

Study drill

Try the exercise below:

1. Make a program that lists the countries in the set below using a while loop.