[Python-ideas] Allow Profile() to be used as a context manager

[David Townshend]

On Wed, Jan 25, 2012 at 10:19 AM, Yuval Greenfield <ubershmekel at gmail.com>wrote:

> On Wed, Jan 25, 2012 at 8:36 AM, David Townshend <aquavitae69 at gmail.com>wrote:
>
>> [...]
>> Any major objections to this?
>>
>>
>
>  At first this sounded like a good idea but 2 things pop to mind:
>
>
>    1. How does one get the pstat profiling output from the context
>    manager? Will printing out the results be the only option?
>
> The same way as currently:

profile = cProfile.Profile()
with profile:
    do_something()

profile.dump_stats(filename)

Perhaps it would be a good idea to provide a convenience function (like
run()), so that:

with cProfile.do(filename):
    do_something()

I don't like calling the function do(), but I can't think of anything
better off-hand, and it illustrates my point.

>
>    1. Usually when I profile I don't want to touch the code at all so
>    eventually if I'll use this context manager it'll be more akin to
>
>
>     with profile.Profiler():
>         main()
>
> Which isn't much of a win over
>
>     profile.run('main()')
>

I agree, but this isn't the use case.


> Now if you're talking about a reentrant profiler, that's interesting:
>
>     profiler = profile.Profiler()
>
>     while is_working:
>         with profiler:
>             do_hard_task()
>
>     do_a_hard_but_i_dont_care_now_task()
>
>     with profiler:
>         do_a_diff_hard_task()
>
>
> and then I can call whatever method is there to get the pstat. If this is
> the vision then it sounds awesome.
>
>
And this is the use case!  I'm not entirely sure how re-entrancy would be
dealt with by the profiler though.  From what I read in the source code it
looks like it would all accumulate, and this is certainly the way I would
expect it to behave, but I'd need to run a few tests to be sure.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-ideas/attachments/20120125/75180ebc/attachment.html>