[Python-ideas] add a time decorator to timeit.py

[Amjad Ben Hedhili]

> Summary: Python's timeit.timeit() has an undocumented feature /
> implementation detail that gives much of what the original poster has
> asked for. Perhaps revising the docs will solve the problem.

although timeit can be used with a callable, you need to create a lambda expression if the function has args:
```
def func_to_time(a, b):
    ...

timeit.timeit(lambda: func_to_time(a, b), globals=globals())
```
and you can't use it as a decorator.
________________________________
De : Python-ideas <python-ideas-bounces+amjadhedhili=outlook.com at python.org> de la part de Jonathan Fine <jfine2358 at gmail.com>
Envoyé : dimanche 7 octobre 2018 09:15
À : python-ideas
Objet : Re: [Python-ideas] add a time decorator to timeit.py

Summary: Python's timeit.timeit() has an undocumented feature /
implementation detail that gives much of what the original poster has
asked for. Perhaps revising the docs will solve the problem.

This thread has prompted me to look at timeit again. Usually, I look
at the command line help first.

>>> import timeit
>>> help(timeit)
    Classes:
        Timer
    Functions:
        timeit(string, string) -> float
        repeat(string, string) -> list
        default_timer() -> float

This time, to my surprise, I found the following works:

>>> def fn(): return 2 + 2
>>> timeit.timeit(fn)
0.10153918000287376

Until today, as I recall, I didn't know this.

Now for: https://docs.python.org/3/library/timeit.html

I don't see any examples there, that show that timeit.timeit can take
a callable as its first argument. So my ignorance can, I hope be
forgiven.

Now for: https://github.com/python/cpython/blob/3.7/Lib/timeit.py#L100

This contains, for both the stmt and setup parameters, explicit tests such as

if isinstance(stmt, str):
    # string case
elif callable(stmt):
    # callable case

So I think it's an undocumented feature, rather than an implementation detail.

And if you're a software historian, now perhaps look at
https://github.com/python/cpython/commits/3.7/Lib/timeit.py

And also, if you wish, for the tests for timeit.py.

--
Jonathan
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