How to Kill a While Loop with a Keystroke in Python?

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To end a while loop prematurely in Python, press CTRL-C while your program is stuck in the loop. This will raise a KeyboardInterrupt error that terminates the whole program. To avoid termination, enclose the while loop in a try/except block and catch the KeyboardInterrupt.

You can see the idea in the following code snippet:

try:
    while True:
        pass # Do something
except KeyboardInterrupt:
    pass

# Do something. Program doesn't terminate after CTRL-C
print('hello world')

The while loop runs forever unless you end it prematurely using the CTRL-C hotkey. But if you do, it prints the string 'hello world' to the shell instead of terminating the whole program:

hello world

Let me show you how this works in the following GIF:

How to Kill a While Loop with a Keystroke in Python?

Programmer Humor

❓ Question: Why do programmers always mix up Halloween and Christmas?
❗ Answer: Because Oct 31 equals Dec 25.

(If you didn’t get this, read our articles on the oct() and int() Python built-in functions!)