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  1. Apache Arrow
  2. ARROW-8442

[Python] NullType.to_pandas_dtype inconsisent with dtype returned in to_pandas/to_numpy

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      There is this behaviour of to_pandas_dtype returning float, while all actual conversions to numpy or pandas use object dtype:

      In [23]: pa.null().to_pandas_dtype()                                                                                                                                                                               
      Out[23]: numpy.float64
      
      In [24]: pa.array([], pa.null()).to_pandas()                                                                                                                                                                       
      Out[24]: Series([], dtype: object)
      
      In [25]: pa.array([], pa.null()).to_numpy(zero_copy_only=False)                                                                                                                                                    
      Out[25]: array([], dtype=object)
      

      So we should probably fix NullType.to_pandas_dtype to return object, which is used in practice.

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              • Assignee:
                jorisvandenbossche Joris Van den Bossche
                Reporter:
                jorisvandenbossche Joris Van den Bossche
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