[
https://issues.apache.org/jira/browse/ARROW-640?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16397116#comment-16397116
]
Antoine Pitrou commented on ARROW-640:
--------------------------------------
[~alexhagerman], you'll need to be careful for hashing to be consistent with
Python scalars (in other words, for every hashable x and y where {{x == y}},
{{hash\(x) == hash\(y)}} should also be true).
The simplest way to do that is probably to convert the Arrow value to a Python
scalar, though that may not be the fastest:
{code:python}
def __hash__(self):
return hash(self.as_py())
{code}
Otherwise you'll need to reproduce the exact hashing algorithm that Python uses.
> [Python] Arrow scalar values should have a sensible __hash__ and comparison
> ---------------------------------------------------------------------------
>
> Key: ARROW-640
> URL: https://issues.apache.org/jira/browse/ARROW-640
> Project: Apache Arrow
> Issue Type: Bug
> Components: Python
> Reporter: Miki Tebeka
> Assignee: Alex Hagerman
> Priority: Major
> Fix For: 0.10.0
>
>
> {noformat}
> In [86]: arr = pa.from_pylist([1, 1, 1, 2])
> In [87]: set(arr)
> Out[87]: {1, 2, 1, 1}
> In [88]: arr[0] == arr[1]
> Out[88]: False
> In [89]: arr
> Out[89]:
> <pyarrow.array.Int64Array object at 0x7f8c8c739e08>
> [
> 1,
> 1,
> 1,
> 2
> ]
> {noformat}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
