bbtfr opened a new issue, #41931: URL: https://github.com/apache/arrow/issues/41931
### Describe the enhancement requested Not sure this is by design or is a bug. ``` import pyarrow as pa t1 = pa.Table.from_pydict({ "a": [1, 2, 3], }) t2 = pa.Table.from_pydict({ "b": [1, 2, 3], }) t3 = concat_tables([t1, t2], promote_options="default") print(t3.to_pydict()) # => {'a': [1, 2, 3, None, None, None], 'b': [None, None, None, 1, 2, 3]} ``` Missing keys at the top level (table? or schema?) is allowed. While at the lower levels (struct?) is not allowed. ``` import pyarrow as pa t1 = pa.Table.from_pydict({ "a": [{"b": 1}], }) t2 = pa.Table.from_pydict({ "a": [{"c": 2}], }) t3 = pa.concat_tables([t1, t2], promote_options="default") # => raise pyarrow.lib.ArrowTypeError: struct fields don't match or are in the wrong order: Input fields: struct<b: int64> output fields: struct<b: int64, c: int64> # And it will work if I do this t3 = pa.concat_tables(t1.to_pylist() + t2.to_pylist()) print(t3.to_pydict()) # => {'a': [{'b': 1, 'c': None}, {'b': None, 'c': 2}]} ``` ### Component(s) Python -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@arrow.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org