6.10. Ending a Loop With
Python, like most programming languages, provides a way to stop a loop before it
would normally finish. The
break keyword immediately stops the execution of
the loop. Program flow then continues with the next line of code below the loop.
1 2 3 4 5 6 7
for iteration in range(42): print('This is iteration number:', iteration+1). if iteration > 4: break print("The loop is done!")
This is iteration number: 1 This is iteration number: 2 This is iteration number: 3 This is iteration number: 4 This is iteration number: 5 This is iteration number: 6 The loop is done!
- Line 2 repeats 6 times with values of
iterationfrom 0 to 5.
- The sixth time through the loop,
iterationis 5 and the condition in line 4 (
iteration > 4) evaluates to
Truefor the first time.
- As a result, the program flow reaches the
breakstatement. The loop immediately stops, even though
range(42)would normally keep the loop going.
- Control moves to the first line of code after the loop.
Why would we need to use
break? After all, we tell Python how many times
the loop should repeat in the
In some cases, you may want to provide a second ending condition. For
example, let’s say you need to search through 100,000 items, and you find the
one you want after 5 iterations. In this case, there is no need to wait for the
loop to finish on its own. Adding a
break statement will speed up your
program, especially if you need to use that large range multiple times.
break statement can also be used within a
There is another command that interrupts a single iteration of a loop but
does not end the loop completely. This is the
continue is rarely used, and we will not discuss it in detail
here. If you are curious, you can find more information at