[ARROW-3002] [Python] Implement better DataType hash function

• Type: Wish
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.11.0
• Component/s: Python
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/19364
• Assignee: Krisztian Szucs
• Reporter: Sam Oluwalana
• Created: 06/Aug/18 20:47
• Updated: 11/Jan/23 07:24
• Resolved: 08/Aug/18 15:10

Description

>>> x = pa.field('record', pa.struct([pa.field('x', pa.int32(), nullable=False)]))
>>> y = pa.field('record', pa.struct([pa.field('x', pa.int32(), nullable=True)]))
>>> z = pa.field('record', pa.struct([pa.field('x', pa.int32(), nullable=True)]))
>>> x.__hash__()
-9223372036569171727
>>> y.__hash__()
285604054
>>> z.__hash__()
285604076
>>> x.type
StructType(struct<x: int32>)
>>> x.type.__hash__()
429437081997812647
>>> y.type.__hash__()
429437081997812647
>>> x
pyarrow.Field<record: struct<x: int32>>
>>> y
pyarrow.Field<record: struct<x: int32>>

Expected:

y._hash() should be the same as z.hash_()

x.type._hash() should be different than y.type.hash_()

Issue Links

• links to: GitHub Pull Request #2385