使用 all 检查所有元素(从2到x-1)是否满足条件:

Use all to check all elements (from 2 upto x-1) met conditions:

>>> [x for x in range(2, 20)
     if all(x % y != 0 for y in range(2, x))]
[2, 3, 5, 7, 11, 13, 17, 19]