python 常用函数 filter
返回sequence中，能使function返回True的值，如果function 为None,则sequence全部返回filter(...)
filter(function or None, sequence) -> list, tuple, or string
Return those items of sequence for which function(item) is true. If
function is None, return the items that are true. If sequence is a tuple
or string, return the same type, else return a list.
>>>
>>>
>>> a=
>>>
>>> filter(None, a)
>>> filter(lambda p:p%2, a)
页:
[1]