Bite-Size Python

10while Loops

In the previous chapter, you learned how to repeat actions in Python using a for loop. However, what should you do if you want your loop to keep repeating while a condition is true? Get ready to learn about Python's other loop, the while loop!

Create a while Loop

Suppose you have a variable x that decreases each time a loop is completed. With each decrease, the string "x is greater than 0" is printed until x is equal to the value 0. How would you go about setting this up? You could use a while loop!

A while loop repeats (or iterates) all actions indented underneath the while loop so long as the condition you define is true. Let's use a while loop to set up the previous logic for the variable x.

>>> x = 5
>>> while x> 0:
        print("x is greater than 0")
        x -= 1
 
 
x is greater than 0
x is greater than 0
x is greater than 0
x is greater than 0
x is greater than 0

In the previous code, the variable x is assigned the value 5. This value is where the while loop starts to count down. Just below the variable assignment, the while loop logic begins with the condition “while x is greater than 0.” What this means is that while the value of x is more than 0, the action inside the while loop happens. In this case, a string is printed, and the value of x is decreased by 1.

As you can see, the string is printed five times given that x is greater than 0 for five of the loops ...