pd.isna(Categorical) casts to object array

In pd.isna, we convert instances of pd.Categorical a numpy array:

Lines 64 to 65 in 07d8c2d

     elif isinstance(obj, list) or hasattr(obj, '__array__'):  
   return _isna_ndarraylike(np.asarray(obj))  
 

We should be able to avoid that by calling obj.values.isna(), which just operates on the codes. To summarize:

So the cases to handle:

>>> s = pd.Categorical(['a', 'b']) >>> pd.isna(s) >>> pd.isna(pd.DataFrame({'A': s})) >>> pd.DataFrame({"A": s}).isna()

Provide feedback

	elif isinstance(obj, list) or hasattr(obj, '__array__'):
	return _isna_ndarraylike(np.asarray(obj))