[jira] [Comment Edited] (ARROW-640) [Python] Arrow scalar values should have a sensible __hash__ and comparison

["Alex Hagerman (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ARROW-640?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16394627#comment-16394627 ] 

Alex Hagerman edited comment on ARROW-640 at 3/11/18 8:13 PM:
--------------------------------------------------------------

I think this has changed since the original ticket. The comparison appears to be working. Tested this with string and numbers. Also getting an error on set now. Going to continue looking into this, but if anybody has thoughts on this I'd be happy to hear them. Also from_pylist appears to have been removed, but I didn't find it searching the change log on github only an addition in 0.3.

 


was (Author: alexhagerman):
I think this has changed since the original ticket. The comparison appears to be working. Tested this with string and numbers. Also getting an error on set now. Going to continue looking into this, but if anybody has thoughts on this I'd be happy to hear them. Also from_pylist appears to have been removed, but I didn't find it searching the change log on github only an addition in 0.3.

 



```python
%load_ext Cython
```


```python
import pyarrow as pa

pylist = [1,1,1,2]
arr = pa.array(pylist)
arr
```




    <pyarrow.lib.Int64Array object at 0x7fd980fb5b38>
    [
      1,
      1,
      1,
      2
    ]




```python
arr[0] == arr[1]
```




    True




```python
set(arr)
```


    ---------------------------------------------------------------------------

    TypeError                                 Traceback (most recent call last)

    <ipython-input-3-ba21c71e79f9> in <module>()
    ----> 1 set(arr)
    

    TypeError: unhashable type: 'pyarrow.lib.Int64Value'



```python
arr_list = pa.from_pylist([1, 1, 1, 2])
```


    ---------------------------------------------------------------------------

    AttributeError                            Traceback (most recent call last)

    <ipython-input-4-30966022c9ed> in <module>()
    ----> 1 arr_list = pa.from_pylist([1, 1, 1, 2])
    

    AttributeError: module 'pyarrow' has no attribute 'from_pylist'

> [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}



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