Make an iterator that filters elements from iterable returning only those for which the predicate is false. If predicate is None, return the items that are false. Roughly equivalent to:
itertools.filterfalse(predicate, iterable)
def filterfalse(predicate, iterable):
filterfalse(lambda x: x%2, range(10)) --> 0 2 4 6 8
if predicate is None:
predicate = bool
for x in iterable:
if not predicate(x):
yield x