davlee1972 commented on issue #13111:
URL: https://github.com/apache/arrow/issues/13111#issuecomment-1644853602
I got a temporary solution which modifies pyarrow.compute.strptime(), but I
can't seem to figure out how to adjust a timestamp array by +/- number of
hours.. tried using pyarrow.compute.add()
Here's the almost completed code..
```
import pyarrow.compute as pc
old_strpttime = pc.strptime
def new_strptime(*args, **kwargs):
if 'format' in kwargs and '%p' in kwargs['format'] and '%I' in
kwargs['format']:
is_am = pc.count_substring(_ts, 'AM')
kwargs['format'] = kwargs['format'].replace('%p','')
strings = pc.replace_substring(pc.replace_substring(args[0], 'AM',
''), 'PM', '')
new_timestamps = old_strpttime(strings, **kwargs)
hour_adjustments = pc.case_when(pc.make_struct(
pc.and_(is_am.cast("bool"), pc.equal(pc.hour(new_timestamps),
12)),
pc.and_(pc.invert(is_am.cast("bool")),
pc.equal(pc.hour(new_timestamps), 12)),
is_am.cast("bool")
),
-12,
0,
0,
12
)
return {'original timestamps': args[0], 'without am|pm':
new_timestamps, 'hours adjusted': hour_to adjust}
else:
return old_strpttime(*args, **kwargs)
pc.strptime = new_strptime
```
and the output with and without AM/PM hour additions..
```
>>> _ts = ["9/03/2023 00:35", "9/03/2023 12:35", "9/03/2023 6:35",
"9/03/2023 18:35"]
>>> _format = "%d/%m/%Y %H:%M"
>>>
>>> pc.strptime(_ts, format= _format, unit='s')
<pyarrow.lib.TimestampArray object at 0x000001D0D0E48880>
[
2023-03-09 00:35:00,
2023-03-09 12:35:00,
2023-03-09 06:35:00,
2023-03-09 18:35:00
]
>>> _ts = ["9/03/2023 12:35 AM", "9/03/2023 12:35 PM", "9/03/2023 6:35 AM",
"9/03/2023 6:35 PM"]
>>> _format = "%d/%m/%Y %I:%M %p"
>>>
>>> pc.strptime(_ts, format= _format, unit='s')
{'original timestamps': ['9/03/2023 12:35 AM', '9/03/2023 12:35 PM',
'9/03/2023 6:35 AM', '9/03/2023 6:35 PM'], 'without am|pm':
<pyarrow.lib.TimestampArray object at 0x000001D0D0E48D00>
[
2023-03-09 12:35:00,
2023-03-09 12:35:00,
2023-03-09 06:35:00,
2023-03-09 06:35:00
], 'hours to adjust': <pyarrow.lib.Int64Array object at 0x000001D0D0E48E20>
[
-12,
0,
0,
12
]}
```
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