#28323 closed Cleanup/optimization (fixed)
Redundant use of normalize() in django.utils.timezone.localtime() and make_naive()
Reported by: | Sergei Zh | Owned by: | nobody |
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Component: | Utilities | Version: | 1.10 |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Accepted | |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
I'm not 100% sure , but I didn't find any test on this and can't think of any.
What the purpose of using timezone.normalize
method after dt.astimezone
if pytz installed?
Current implementation of datetime.astimezone
(according to python 2/3 docs):
def astimezone(self, tz): if self.tzinfo is tz: return self # Convert self to UTC, and attach the new time zone object. utc = (self - self.utcoffset()).replace(tzinfo=tz) # Convert from UTC to tz's local time. return tz.fromutc(utc)
The implementation of normalize
method for StaticTzInfo is astimezone
:
if dt.tzinfo is self: return dt if dt.tzinfo is None: raise ValueError('Naive time - no tzinfo set') return dt.astimezone(self)
And for DstTzInfo normalize
implementation is the same as datetime.astimezone
:
if dt.tzinfo is None: raise ValueError('Naive time - no tzinfo set') # Convert dt in localtime to UTC offset = dt.tzinfo._utcoffset dt = dt.replace(tzinfo=None) dt = dt - offset # convert it back, and return it return self.fromutc(dt)
I've checked pytz 2011k and 2017.2 versions, looks like this code has never changed.
Also I found this conversation https://answers.launchpad.net/pytz/+question/249229
Change History (4)
comment:1 by , 8 years ago
Has patch: | set |
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Summary: | Redundant use of `normalize` in `django.utils.localtime` → Redundant use of normalize() in django.utils.timezone.localtime() |
Triage Stage: | Unreviewed → Accepted |
Type: | Uncategorized → Cleanup/optimization |
comment:2 by , 8 years ago
Summary: | Redundant use of normalize() in django.utils.timezone.localtime() → Redundant use of normalize() in django.utils.timezone.localtime() and make_naive() |
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comment:4 by , 8 years ago
I was merely following the pytz docs, before they were updated in version 2016.4.
PR -- the tests seems to pass, so unless we're missing a test case to show why
normalize()
is needed, I'd think your analysis is correct.