[ARROW-1718] [Python] Implement casts from timestamp to date32/date64 and support in Array.from_pandas

• Type: New Feature
• 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/15613
• Assignee: Wes McKinney
• Reporter: Bryan Cutler
• Created: 23/Oct/17 22:55
• Updated: 11/Jan/23 07:16
• Resolved: 30/Oct/17 07:51

Description

When calling Array.from_pandas with a pandas.Series of dates and specifying the desired pyarrow type, an error occurs. If the type is not specified then from_pandas will interpret the data as a timestamp type.

import pandas as pd
import pyarrow as pa
import datetime

arr = pa.array([datetime.date(2017, 10, 23)])
c = pa.Column.from_array("d", arr)

s = c.to_pandas()
print(s)
# 0   2017-10-23
# Name: d, dtype: datetime64[ns]

result = pa.Array.from_pandas(s, type=pa.date32())
print(result)
"""
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pyarrow/array.pxi", line 295, in pyarrow.lib.Array.__repr__ (/home/bryan/git/arrow/python/build/temp.linux-x86_64-2.7/lib.cxx:26221)
  File "/home/bryan/.local/lib/python2.7/site-packages/pyarrow-0.7.2.dev21+ng028f2cd-py2.7-linux-x86_64.egg/pyarrow/formatting.py", line 28, in array_format
    values.append(value_format(x, 0))
  File "/home/bryan/.local/lib/python2.7/site-packages/pyarrow-0.7.2.dev21+ng028f2cd-py2.7-linux-x86_64.egg/pyarrow/formatting.py", line 49, in value_format
    return repr(x)
  File "pyarrow/scalar.pxi", line 63, in pyarrow.lib.ArrayValue.__repr__ (/home/bryan/git/arrow/python/build/temp.linux-x86_64-2.7/lib.cxx:19535)
  File "pyarrow/scalar.pxi", line 137, in pyarrow.lib.Date32Value.as_py (/home/bryan/git/arrow/python/build/temp.linux-x86_64-2.7/lib.cxx:20368)
ValueError: year is out of range
"""

Issue Links

• is related to: ARROW-1680 [Python] Timestamp unit change not done in from_pandas() conversion
• links to: GitHub Pull Request #1258