Python 3.5 filter

filter(F, L)

F: 函数。L：范围

filter的功能是：用函数F把L范围内的参数做过滤

通常和list一起使用，把过滤后的参数做成列表

list(filter(lambda n:not (n%3),range(0,100)))

表示的是找出0-100的整数中能被3整除的数

等同于：

[i for i in range(0,100) if not (i%3)]

>>> list(filter(lambda n:not(n%3),range(0,100)))
[0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99]
>>> [i for i in range(0,100) if not(i%3)]
[0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99]
>>>