Learn Web Development with Python

The while loop

In the preceding pages, we saw the for loop in action. It's incredibly useful when you need to loop over a sequence or a collection. The key point to keep in mind, when you need to be able to discriminate which looping construct to use, is that the for loop rocks when you have to iterate over a finite amount of elements. It can be a huge amount, but still, something that ends at some point.

There are other cases though, when you just need to loop until some condition is satisfied, or even loop indefinitely until the application is stopped, such as cases where we don't really have something to iterate on, and therefore the for loop would be a poor choice. But fear not, for these cases, Python provides us with the while loop. ...