3.15 break and continue Statements

The break and continue statements alter a loop’s flow of control. Executing a break statement in a while or for immediately exits that statement. In the following code, range produces the integer sequence 0–99, but the loop terminates when number is 10:

In [1]: for number in range(100):
   ...:     if number == 10:
   ...:         break
   ...:     print(number, end=' ')
   ...:
0 1 2 3 4 5 6 7 8 9

In a script, execution would continue with the next statement after the for loop. The while and for statements each have an optional else clause that executes only if the loop terminates normally—that is, not as a result of a break. We explore this in the exercises.

Executing a continue statement in a while or for loop skips the remainder of the loop’s suite. In a while, the condition is then tested to determine whether the loop should continue executing. In a for, the loop processes the next item in the sequence (if any):

In [2]: for number in range(10):
...:     if number == 5:
...:         continue
...:     print(number, end=' ')
...:
0 1 2 3 4 6 7 8 9