BUG (string dtype): comparison of string column to mixed object column fails (original) (raw)

At the moment you can freely compare with mixed object dtype column:

ser_string = pd.Series(["a", "b"]) ser_mixed = pd.Series([1, "b"]) ser_string == ser_mixed 0 False 1 True dtype: bool

But with the string dtype enabled (using pyarrow), this now raises an error:

pd.options.future.infer_string = True ser_string = pd.Series(["a", "b"]) ser_mixed = pd.Series([1, "b"]) ser_string == ser_mixed ... File ~/scipy/repos/pandas/pandas/core/arrays/arrow/array.py:510, in ArrowExtensionArray._box_pa_array(cls, value, pa_type, copy) ... --> 510 pa_array = pa.array(value, from_pandas=True) ... ArrowInvalid: Could not convert 'b' with type str: tried to convert to int64

This happens because the ArrowEA tries to convert the other operand to Arrow as well, which fails for mixed types.

In general, I think our rule is that == comparison never fails, but then just gives False for when values are not comparable.