ENH: Add additional options to nonexistent in tz_localize #24493
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pandas/_libs/tslibs/conversion.pyx
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| shift_forward = True | ||
| elif nonexistent == 'shift_backward': | ||
| shift_backward = True | ||
| elif isinstance(nonexistent, timedelta): |
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PyDelta_Check(nonexistent)
| - 'NaT' will return NaT where there are nonexistent times | ||
| - timedelta objects will shift nonexistent times by the timedelta |
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IIRC cython doesn't play nicely with docstring templating; might be worth opening an issue over there to request it
Codecov Report
@@ Coverage Diff @@
## master #24493 +/- ##
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- Coverage 92.31% 43.06% -49.26%
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Files 166 166
Lines 52412 52415 +3
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- Hits 48382 22570 -25812
- Misses 4030 29845 +25815
Continue to review full report at Codecov.
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Codecov Report
@@ Coverage Diff @@
## master #24493 +/- ##
==========================================
+ Coverage 92.33% 92.33% +<.01%
==========================================
Files 166 166
Lines 52544 52547 +3
==========================================
+ Hits 48517 48520 +3
Misses 4027 4027
Continue to review full report at Codecov.
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| shift_forward = True | ||
| elif nonexistent == 'shift_backward': | ||
| shift_backward = True | ||
| elif PyDelta_Check(nonexistent): |
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is there a practical use of this?
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From the original enhancement request #24466 (comment), there was no way to shift backwards, moreover by a specified amount. I can see how it would be valuable to shift nonexistent times forward or backwards by a specified amount instead of the closest time. (e.g. I want times on the half hours, so be able to shift times to 1:30 or 3:30 and not just 1:59 or 3:00)
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is this duplicating shift_backwards though? this seems unecessarily complex to do anything more that doing a snap, eg. to a valid time (forward or backwards). shifting is an independent operation.
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IMO it didn't add too much more complexity to the code, but here was @sdementen use case:
I do some calculation on a local timestamp without tz, that I shift by 2 hours backward (to say "take it two hours before") and then I localize and get a NonExistentTimeError (e.g. Timestamp("2018-03-25T04:33:00") - DateOffset(hours=2)). I would like to get as a result of the tz_localize('CET'), the time "2018-03-25T01:33:00+0100" or "2018-03-25T03:33:00+0200" (and not "2018-03-25T01:59:59.99999+0100" or "2018-03-25T03:00:00+0200")
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I can see how in principle how it's very similar to shift_forward/ shift_backwards then adding an offset, but it can be easier determining how you want to shift from a nonexistent time compared to a nonexistent time that has been snapped to 1:59 or 3:00.
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@sdementen care to chime in on thoughts?
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thanks @mroeschke |
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can you merge master |
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thanks @mroeschke |
git diff upstream/master -u -- "*.py" | flake8 --diffPer @sdementen suggestion, adding additional options for
nonexistentthat would prove more useful. Let me know if this is what you had in mind.shiftis nowshift_forward: shift nonexistent times forward to the closest real timeshift_backward: shift nonexistent times backwards to the closest real timetimedelta object: shifts nonexistent times by the timedelta duration