Tutorials
python

Python While Loops

Learn how while loop works in Python.

Below you can find the example from the video where the error variable, initially equal to 50.0, is divided by 4 and printed out on every run:

error = 50.0
while error > 1 :
    error = error / 4
    print(error)

This example will come in handy, because it's time to build a while loop yourself! We're going to code a while loop that implements a very basic control system for an inverted pendulum. If there's an offset from standing perfectly straight, the while loop will incrementally fix this offset.

Note that if your while loop takes too long to run, you might have made a mistake. In particular, remember to indent the contents of the loop!

Exercise

TRY IT YOURSELF: Access the exercise in our Intermediate Python course here.

  • Create the variable offset with an initial value of 8.
  • Code a while loop that keeps running as long as offset is not equal to 0. Inside the while loop:
    • Print out the sentence "correcting...".
    • Next, decrease the value of offset by 1. You can do this with offset = offset - 1.
    • Finally, still within your loop, print out offset so you can see how it changes.
# Initialize offset


# Code the while loop

Video

To learn more about while loops, please see this video from our course Intermediate Python.

This content is taken from DataCamp’s Intermediate Python course by Hugo Bowne-Anderson.