time test for identity searches

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from itertools import chain

def test_really_in(y, xs):
    for x in xs:
        if y is x: return True
    return False

def test_filtered_really_in(y, xs):
    return filter(lambda e: e is y, xs)

def test_list_really_in(y, xs):
    return [x for x in xs if y is x]

def test_any_suggestion(y, xs):
    return any(e is y for e in xs)

if __name__ == '__main__':
    from timeit import Timer
    itercnt = 10000
    expression = "%s(True, chain(xrange(0, 1000), [True]))"
    impst = "from __main__ import %s, chain"
    funcs = [x for x in globals().keys() if x.startswith('test_')]
    for f in funcs:
        t = Timer(expression % f, impst % f)
        print f, t.timeit(itercnt)


Results are:

test_filtered_really_in 1.47374796867
test_list_really_in 0.825389862061
test_really_in 0.822808980942
test_any_suggestion 1.01692414284