[ARROW-3448] [Python] Pandas roundtrip doesn't preserve list of datetime objects

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/19770
• Assignee: Unassigned
• Reporter: Krisztian Szucs
• Created: 06/Oct/18 07:44
• Updated: 11/Jan/23 07:27

Description

Adding the following to the pandas_example.py::dataframe_with_lists functionn:

datetime_data = [
     [datetime(2015, 1, 5, 12, 0, 0), datetime(2020, 8, 22, 10, 5, 0)],
     [datetime(2024, 5, 5, 5, 49, 1), datetime(2015, 12, 24, 22, 10, 17)],
     [datetime(1996, 4, 30, 2, 38, 11)],
     None,
     [datetime(1987, 1, 27, 8, 21, 59)]
]

type = pa.timestamp('s'|'ms'|'us'|'ns')

breaks the tests cases, because the roundtrip doesn't preserve the object type.

Issue Links

• relates to: ARROW-5359 [Python] timestamp_as_object support for pa.Table.to_pandas in pyarrow
• links to: GitHub Pull Request #10866