Python中有关filter的用法详解

1 class filter(object)
2  |  filter(function or None, iterable) --> filter object
3  |  
4  |  Return an iterator yielding those items of iterable for which function(item)
5  |  is true. If function is None, return the items that are true.

1 In [2]: import re
2 In [3]: i = re.split(',',"123,,123213,,,123213,")
3 In [4]: i4 Out[4]: ['123', '', '123213', '', '', '123213', '']

1 In [7]: print(*filter(None, i))
2 123 123213 123213

In [9]: print(list(filter(lambda x:x=='', i)))
['', '', '', '']