【python】官网例子

地址:https://docs.python.org/3/tutorial/controlflow.html

>>> 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

 

 为什么range(2,2)不会报错,它返回的是一个空迭代器,for循环作用于空的迭代器上一次也不会执行,而是直接结束

 
posted @ 2021-06-22 17:53  learning365  阅读(68)  评论(0编辑  收藏  举报