timeit

timeit.py

# https://docs.python.org/2/library/timeit.html
>>> def foo(n):
...     res = []
...     for i in range(n):      res.append(n)
...     return res
...
>>> def foo2(n):
...     return [i for i in range(n)]
...
>>> foo(10) == foo2(10)
False
>>> def foo(n):
...     res = []
...     for i in range(n):      res.append(i)
...     return res
...
>>> def foo2(n):
...     return [i for i in range(n)]
...
>>> foo(10) == foo2(10)
True
>>> import timeit
>>> timeit.timeit(stmt='foo(10000)', setup='from __main__ import foo', number=100)
0.11489105224609375
>>> timeit.timeit(stmt='foo2(10000)', setup='from __main__ import foo2', number=100)
0.04136300086975098