I think that a time decorator will be a useful addition to the sandard library, as i find the current way of measuring execution time a bit tedious:

timeit.timeit("fun_to_time(a, b)", setup="from __main__ import a, b", number=1)

compared to:

@timef
def fun_to_time(a, b):
    ...

or

timef(print)("Hello world!").
I already made a basic implementation of it, and it's working well.