[ARROW-1906] [Python] Creating a pyarrow.Array with timestamp of different unit is not casted

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8.0
• Component/s: Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/15635
• Assignee: Wes McKinney
• Reporter: Bryan Cutler
• Created: 08/Dec/17 19:02
• Updated: 11/Jan/23 07:17
• Resolved: 11/Dec/17 15:06

Description

This is similar to ARROW-1680 but slightly different in that an error is not raised but the unit will still remain unchanged only when using a timezone

In [47]: us_with_tz = pa.timestamp('us', tz='America/New_York')

In [48]: s = pd.Series([val])

In [49]: s_nyc = s.dt.tz_localize('tzlocal()').dt.tz_convert('America/New_York')

In [50]: arr = pa.Array.from_pandas(s_nyc, type=us_with_tz)

In [51]: arr.type
Out[51]: TimestampType(timestamp[ns, tz=America/New_York])

In [52]: arr2 = pa.Array.from_pandas(s, type=pa.timestamp('us'))

In [53]: arr2.type
Out[53]: TimestampType(timestamp[us])

There is an easy workaround to apply the cast after creating the pyarrow.Array, which seems to work fine

In [54]: arr = pa.Array.from_pandas(s_nyc).cast(us_with_tz, safe=False)

In [55]: arr.type
Out[55]: TimestampType(timestamp[us, tz=America/New_York])

Issue Links

• links to: GitHub Pull Request #1411