[ARROW-1628] [Python] Incorrect serialization of numpy datetimes.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: Python
• Labels: pyarrow-serialization
• External issue URL: https://github.com/apache/arrow/issues/17639
• Assignee: Unassigned
• Reporter: Robert Nishihara
• Created: 30/Sep/17 17:03
• Updated: 11/Jan/23 07:15
• Resolved: 17/Feb/21 16:05

Description

See https://github.com/ray-project/ray/issues/1041.

The issue can be reproduced as follows.

import pyarrow as pa
import numpy as np

t = np.datetime64(datetime.datetime.now())

print(type(t), t)  # <class 'numpy.datetime64'> 2017-09-30T09:50:46.089952

t_new = pa.deserialize(pa.serialize(t).to_buffer())

print(type(t_new), t_new)  # <class 'int'> 0