apache / apache/arrow

[Python] Creating an array from a null list scalar fails

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#40,319 1 comment 1 reaction 0 assignees View on GitHub
Component: Python Type: bug
Dominant language
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Description

### Describe the bug, including details regarding any error messages, version, and platform.

Currently pyarrow fails to construct an array from a null list scalar:
```
>>> import pyarrow as pa
>>> pa.__version__
'15.0.0'
>>> pa.array([pa.scalar(None, pa.list_(pa.int64()))])
Traceback (most recent call last):
File "", line 1, in
File "pyarrow/array.pxi", line 344, in pyarrow.lib.array
File "pyarrow/array.pxi", line 42, in pyarrow.lib._sequence_to_array
File "pyarrow/error.pxi", line 154, in pyarrow.lib.pyarrow_internal_check_status
File "pyarrow/types.pxi", line 88, in pyarrow.lib._datatype_to_pep3118
File "pyarrow/scalar.pxi", line 685, in pyarrow.lib.ListScalar.__len__
TypeError: object of type 'NoneType' has no len()
```

This may be worked around by directly constructing the array and specifying the type when this case is detected:
```
>>> pa.array([None], type=pa.list_(pa.int64()))

[
null
]
```

### Component(s)

Python

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