Python For Kids For Dummies
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Usually you get called rude if you interrupt. Not in programming. Are you ready to create a program that never finishes by itself (called an infinite loop)? This section shows you how to force it to stop.

Forcing a stop is useful when your program locks up and won't respond. The trick is to press Ctrl+C (the Ctrl key and the C key at the same time; don't press the Shift key). Make sure the Python window is active (by clicking the window) when you do — or you might close the wrong program!

Here's how you write an infinite loop program:

  1. Type while True: and press Enter.

  2. Press the spacebar four times.

  3. Type pass.

  4. Press Enter twice.

This is what you'll see:

>>> while True:
… pass
…

The Python interpreter is unresponsive. If you try to get it to assign or print something, nothing happens. It lays there like a lump. The usual >>> prompt isn’t there. You may also hear your computer laboring.

Quick: Press Ctrl+C to break out of the loop and get control back. You get this when you do it:

>>> while True:
…       pass
…
^CTraceback (most recent call last):
  File "", line 1, in 
KeyboardInterrupt
>>>

About This Article

This article is from the book:

About the book author:

Brendan Scott is a dad who loves Python and wants kids to get some of its magic too. He started pythonforkids.brendanscott.com to help teach his oldest child to code. He maintains it to help other young people learn Python.

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