iterable if function(item)]`` if function is not ``None`` and ``[item for item
in iterable if item]`` if function is ``None``.
- See :func:`itertools.ifilterfalse` for the complementary function that returns
- elements of *iterable* for which *function* returns false.
+ See :func:`itertools.ifilter` and :func:`itertools.ifilterfalse` for iterator
+ versions of this function, including a variation that filters for elements
+ where the *function* returns false.
.. function:: float([x])