PERF: leverage tzlocal package to provide 2000x speedup for dateutil.tz.tzlocal operations #24737
Conversation
Codecov Report
@@ Coverage Diff @@
## master #24737 +/- ##
==========================================
- Coverage 92.39% 92.38% -0.01%
==========================================
Files 166 166
Lines 52358 52358
==========================================
- Hits 48374 48373 -1
- Misses 3984 3985 +1
Continue to review full report at Codecov.
|
Codecov Report
@@ Coverage Diff @@
## master #24737 +/- ##
===========================================
- Coverage 92.37% 42.75% -49.62%
===========================================
Files 166 171 +5
Lines 52408 52582 +174
===========================================
- Hits 48412 22484 -25928
- Misses 3996 30098 +26102
Continue to review full report at Codecov.
|
jschendel
added
Datetime
ci/deps/azure-27-compat.yaml
Outdated
| @@ -10,10 +10,11 @@ dependencies: | |||
| - numpy=1.12.0 | |||
| - openpyxl=2.5.5 | |||
| - pytables=3.4.2 | |||
| - python-dateutil=2.5.0 | |||
There was a problem hiding this comment.
We would need to discuss bumping up our minimum version of dateutil
pandas/_libs/tslibs/timezones.pyx
Outdated
| @@ -34,6 +36,38 @@ cdef inline bint is_tzlocal(object tz): | |||
| return isinstance(tz, _dateutil_tzlocal) | |||
|
|
|||
|
|
|||
| cpdef bint have_tzlocal_package(): | |||
There was a problem hiding this comment.
Couldn't this just be run once with the imports and just assign the sentinel value?
pandas/_libs/tslibs/timezones.pyx
Outdated
|
|
||
| try: | ||
| return pytz.timezone(tzlocal_tz) | ||
| except pytz.exceptions.UnknownTimeZoneError: |
There was a problem hiding this comment.
Don't think you need the exceptions here.
There was a problem hiding this comment.
tzlocal will report the system tz even if it isn't a valid pytz tz. For example, we'll hit this case if /etc/timezone contains foo/bar or, more likely, an ambiguous user timezone like STD.
| @@ -820,7 +820,8 @@ def test_timetz_accessor(self, tz_naive_fixture): | |||
|
|
|||
| index = DatetimeIndex(['2018-06-04 10:20:30', pd.NaT], tz=tz) | |||
| result = index.timetz | |||
|
|
|||
| print('result', result) | |||
| @@ -536,6 +536,8 @@ def test_dt_timetz_accessor(self, tz_naive_fixture): | |||
| expected = Series([time(23, 56, tzinfo=tz), time(21, 24, tzinfo=tz), | |||
| time(22, 14, tzinfo=tz)]) | |||
| result = s.dt.timetz | |||
| print('result', result) | |||
|
@mroeschke Agreed, it's worth mentioning that this mostly fixes the top performance regression between It'd be relatively simple to vendor it as it's only a handful of files. It's MIT licensed, so should be fine but worth mentioning now. I haven't been able to reproduce the |
|
if we bump to 2.6.0 would u still need tzlocal? |
|
I generally like the idea of avoiding returning Do we have any read on how accurate/canonical tzlocal.get_localzone is? For instance I just called it and got "America/Los_Angeles" back, while I was expecting to get "US/Pacific". Do/should we care about that distinction? Also FWIW, the way dateutil decides to return a tzlocal() object is based on looking at |
|
@jreback Yes, there's just a hard-to-reproduce conflict with 2.5.0-2.5.3. Not sure how serious it is at this point. @jbrockmendel Regarding accuracy, it's pulling from system files like There's no distinction between |
|
Although tzlocal hurts portability (unless that's the intension), I think pandas should ensure that timezones in == timezones out and shouldn't make any assumptions or transformation when returning the timezone (i.e tzlocal in, tzlocal out; US/Pacific in, US/Pacific out), which I can see your PR does @qwhelan . Overall agreed that I'd be great to address this regression. Shot in the dark: I think the proper way to compare dateutil tzs is with |
use |
qwhelan
force-pushed
the
tzlocal
branch
2 times, most recently
from
64e8788 to
79bb80e
Compare
|
Hello @qwhelan! Thanks for updating the PR.
Comment last updated on February 05, 2019 at 07:53 Hours UTC |
qwhelan
force-pushed
the
tzlocal
branch
7 times, most recently
from
3c66b5f to
702b29a
Compare
|
@jreback I'm finally able to reproduce the |
qwhelan
force-pushed
the
tzlocal
branch
3 times, most recently
from
9c695f7 to
6e37589
Compare
…tz.tzlocal operations
|
put in pandas/tseries/_tzlocal.py i think - see how that works |
|
@jreback How about |
|
sure that’s ok too |
Is there anything in particular that bears cythonizing? |
|
Haven't looked closely, but I imagine most all functions here can be |
| @@ -17,7 +17,7 @@ cimport numpy as cnp | |||
| from numpy cimport int64_t | |||
| cnp.import_array() | |||
|
|
|||
|
|
|||
| cimport pandas._libs.tslibs | |||
There was a problem hiding this comment.
Cython was making noise about this when running under 2.7; looks like it doesn't raise the same error under 3. Will remove this.
| @@ -3,6 +3,9 @@ | |||
| cpdef bint is_utc(object tz) | |||
| cdef bint is_tzlocal(object tz) | |||
|
|
|||
| cpdef object get_tzlocal_tz(object tz) | |||
| cpdef _set_tzlocal_tz(object tz) | |||
There was a problem hiding this comment.
Is this used externally? If so, it shouldn’t be private. If not, it shouldn’t be in the pxd file.
There was a problem hiding this comment.
It's currently being used to assist in testing, where we cycle through all pytz timezones and check equivalence against tzlocal.
| @@ -0,0 +1,5 @@ | |||
| import sys | |||
There was a problem hiding this comment.
I wouldn't put this in src (which is not a real package, nor do we want it to be), rather just in pandas/_libs/tzlocal is fine
There was a problem hiding this comment.
alternative would be something like pandas/vendored/. pd.io.clipboard would also belong in such a directory.
There was a problem hiding this comment.
call this pandas/_vendored/ (explicity private)
| @@ -0,0 +1,5 @@ | |||
| import sys | |||
There was a problem hiding this comment.
can you make it clear that this is a vendored copy
| @@ -34,6 +37,25 @@ cdef inline bint is_tzlocal(object tz): | |||
| return isinstance(tz, _dateutil_tzlocal) | |||
|
|
|||
|
|
|||
| cpdef object get_tzlocal_tz(object tz): | |||
| global tzlocal_tz | |||
There was a problem hiding this comment.
is this to prevent import issues?
|
@qwhelan can you merge master and address build failures? |
| @@ -0,0 +1,5 @@ | |||
| import sys | |||
There was a problem hiding this comment.
call this pandas/_vendored/ (explicity private)
|
can you merge master and update |
1 similar comment
|
can you merge master and update |
|
closing as stale. nice idea though, pls ping if you can continue. |
This is a follow-up to #24491, where it was noted that
tzlocaloperations are notably slower:This PR makes them indistinguishable from other timezones:
To do this, we add a new optional dependency:
tzlocal. This package queries the OS to try and identify apytzcompatible timezone name for the local timezone. If this is successful, we can use thepytztimezone instead ofdateutil.tz.tzlocal(), yielding a huge speedup as the latter invokesdatetime.datetime(). In cases where the local timezone is also UTC, further speedups are possible.In all cases, the
tzlocal()object is maintained as the.tzto preserve any semantic meaning.One unresolved issue is an incompatibility with
python-dateutilversions prior to2.6.0. I'm unable to reproduce the error locally, but can repeatably get this error on Travis:While this only shows up on the 2.7 build, I believe this is due to it being the only one actually building against
python-dateutil=2.5.0. Any version>=2.6.0does not exhibit this error.Finally, here is the
asvbenchmark againstv0.24.0rc1:git diff upstream/master -u -- "*.py" | flake8 --diff