| msg155831 - (view) |
Author: STINNER Victor (vstinner) *  |
Date: 2012-03-15 00:52 |
| Python 3.3 has 3 functions to get time: - time.clock() - time.steady() - time.time() Antoine Pitrou suggested to deprecated time.clock() in (issue #10278). "The problem is time.clock(), since it does two wildly different things depending on the OS. I would suggest to deprecate time.clock() at the same time as we add time.wallclock(). For the Unix-specific definition of time.clock(), there is already os.times() (which gives even richer information)." (time.wallclock was the old name of time.steady) |
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| msg155866 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2012-03-15 06:37 |
| STINNER Victor wrote: > > New submission from STINNER Victor <victor.stinner@gmail.com>: > > Python 3.3 has 3 functions to get time: > > - time.clock() > - time.steady() > - time.time() > > Antoine Pitrou suggested to deprecated time.clock() in (issue #10278). > > "The problem is time.clock(), since it does two wildly different things > depending on the OS. I would suggest to deprecate time.clock() at the same time as we add time.wallclock(). For the Unix-specific definition of time.clock(), there is already os.times() (which gives even richer information)." > > (time.wallclock was the old name of time.steady) Strong -1 on this idea. time.clock() has been in use for ages in many many scripts. We don't want to carelessly break all those. |
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| msg155873 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2012-03-15 09:31 |
| > time.clock() has been in use for ages in many many scripts. > We don't want to carelessly break all those. I don't want to remove the function, just mark it as deprecated to avoid confusion. It will only be removed from the next major Python. |
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| msg156063 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2012-03-16 18:05 |
| STINNER Victor wrote: > > STINNER Victor <victor.stinner@gmail.com> added the comment: > >> time.clock() has been in use for ages in many many scripts. >> We don't want to carelessly break all those. > > I don't want to remove the function, just mark it as deprecated to > avoid confusion. It will only be removed from the next major Python. Why ? There's no other single function providing the same functionality, so it's not even a candidate for deprecation. Similar functionality is available via several different functions, but that's true for a lot functions in th stdlib. |
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| msg156335 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2012-03-19 12:46 |
| > There's no other single function providing the same functionality time.clock() is not portable: it is a different clock depending on the OS. To write portable code, you have to use the right function: - time.time() - time.steady() - os.times(), resource.getrusage() On Windows, time.clock() should be replaced by time.steady(). On UNIX, time.clock() can be replaced with "usage=os.times(); usage[0]+usage[1]" for example. Which kind of use case is not covered by these functions? |
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| msg156341 - (view) |
Author: Marc-Andre Lemburg (lemburg) * |
Date: 2012-03-19 14:14 |
| STINNER Victor wrote: > > STINNER Victor <victor.stinner@gmail.com> added the comment: > >> There's no other single function providing the same functionality > > time.clock() is not portable: it is a different clock depending on the OS. To write portable code, you have to use the right function: > > - time.time() > - time.steady() > - os.times(), resource.getrusage() time.clock() does exactly what the docs say: you get access to a CPU timer. It's normal that CPU timers work differently on different OSes. > On Windows, time.clock() should be replaced by time.steady(). What for ? time.clock() uses the same timer as time.steady() on Windows, AFAICT, so all you change is the name of the function. > On UNIX, time.clock() can be replaced with "usage=os.times(); usage[0]+usage[1]" for example. And what's the advantage of that over using time.clock() directly ? |
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| msg157519 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2012-04-04 23:43 |
| I misunderstood the time.clock() function. It counts the CPU time while the process is active, whereas a monotonic clock counts elapsed time even during a sleep. time.clock() and time.monotonic() are different clocks for different purposes. I wrote the PEP 418 which contains a list of all available OS clocks. It lists monotonic clocks, but also "process time" and "thread time" clocks. And it has a "Deferred API: time.perf_counter()" section. Something can be done to provide portable functions to get the user and system times. See for example Tools/pybench/systimes.py written by Marc-Andre Lemburg. Python 3.3 gives access to clock_gettime(CLOCK_PROCESS_CPUTIME_ID) and clock_gettime(CLOCK_THREAD_CPUTIME_ID). |
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| msg157520 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2012-04-04 23:49 |
| > Something can be done to provide portable functions to get > the user and system times. Lib/profile.py tests also various functions to choose the best one in Profile constructor. |
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| msg159555 - (view) |
Author: Roundup Robot (python-dev)  |
Date: 2012-04-29 00:53 |
| New changeset 314c3faea2fb by Victor Stinner in branch 'default': Close #14309: Deprecate time.clock() http://hg.python.org/cpython/rev/314c3faea2fb |
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| msg159556 - (view) |
Author: STINNER Victor (vstinner) * |
Date: 2012-04-29 00:54 |
| The PEP 418 has been accepted: read it to understand why time.clock() is now deprecated. |
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