[ARROW-4324] [Python] Array dtype inference incorrect when created from list of mixed numpy scalars

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.11.1
• Fix Version/s: 0.14.0
• Component/s: Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/20895
• Assignee: Wes McKinney
• Reporter: Keith Kraus
• Created: 22/Jan/19 17:49
• Updated: 11/Jan/23 07:33
• Resolved: 12/Jun/19 22:14

Description

Minimal reproducer:

import pyarrow as pa
import numpy as np

test_list = [np.dtype('int32').type(10), np.dtype('float32').type(0.5)]
test_array = pa.array(test_list)

# Expected
# test_array
# <pyarrow.lib.DoubleArray object at 0x7f009963bf48>
# [
#   10,
#   0.5
# ]

# Got
# test_array
# <pyarrow.lib.Int32Array object at 0x7f009963bf48>
# [
#   10,
#   0
# ]

Issue Links

• relates to: ARROW-5566 [Python] Overhaul type unification from Python sequence in arrow::py::InferArrowType
• links to: GitHub Pull Request #4527