BUG: writing an empty dataframe with an object column with use_arrow fails

[theroggy]

When an empty dataframe (no rows) with an "object" dtype column is written using use_arrow=True, this leads to this type of error: pyogrio.errors.FieldError: Error while creating field from Arrow for field 3 with name 'HFDTLT' and type n (Type 'n' for field HFDTLT is not supported.).

The same problem occurs when an object type column contains only None values.

Looking deeper into this, the issue is that in the table returned by pyarrow.Table.from_pandas, the object column is returned as having the "null" type... and this "null" type is not supported by GDAL.

pyogrio/pyogrio/geopandas.py

Line 623 in ed39ad7

table = pa.Table.from_pandas(df, preserve_index=False)