break

break 語句和 C 中的類似，用於跳出最近的一級 for 或 while 循環。

循環可以有一個 else 子句；它在循環叠代完整個列表（對於 for ）或執行條件為 false （對於 while ）時執行，但循環被 break 中止的情況下不會執行。以下搜索素數的示例程序演示了這個子句:

>>> for n in range(2, 10):
...     for x in range(2, n):
...         if n % x == 0:
...             print(n, ‘equals‘, x, ‘*‘, n//x)
...             
 
break
...     else:
...         # loop fell through without finding a factor
...         print(n, ‘is a prime number‘)
...
2 is a prime number
3 is a prime number
4 equals 2 * 2
5 is a prime number
6 equals 2 * 3
7 is a prime number
8 equals 2 * 4
9 equals 3 * 3

(Yes, 這是正確的代碼。看仔細：else 語句是屬於 for 循環之中， 不是

continue

continue 語句是從 C 中借鑒來的，它表示循環繼續執行下一次叠代:

>>> for num in range(2, 10):
...     if num % 2 == 0:
...         print("Found an even number", num)
...         continue
...     print("Found a number", num)
Found an even number 2
Found a number 3
Found an even number 4
Found a number 
 
5
Found an even number 6
Found a number 7
Found an even number 8
Found a number 9

Python 基礎（三）——流程控制之break 、continue 、else