Marco Neumann created ARROW-6872: ------------------------------------ Summary: [C++][Python] Empty table with dictionary-columns raises ArrowNotImplementedError Key: ARROW-6872 URL: https://issues.apache.org/jira/browse/ARROW-6872 Project: Apache Arrow Issue Type: Bug Components: C++, Python Affects Versions: 0.15.0 Reporter: Marco Neumann
h2. Abstract As a pyarrow user, I would expect that I can create an empty table out of every schema that I created via pandas. This does not work for dictionary types (e.g. {{"category"}} dtypes). h2. Test Case This code: {code:python} import pandas as pd import pyarrow as pa df = pd.DataFrame({"x": pd.Series(["x", "y"], dtype="category")}) table = pa.Table.from_pandas(df) schema = table.schema table_empty = schema.empty_table() # boom {code} produces this exception: {noformat} Traceback (most recent call last): File "arrow_bug.py", line 8, in <module> table_empty = schema.empty_table() File "pyarrow/types.pxi", line 860, in __iter__ File "pyarrow/array.pxi", line 211, in pyarrow.lib.array File "pyarrow/array.pxi", line 36, in pyarrow.lib._sequence_to_array File "pyarrow/error.pxi", line 86, in pyarrow.lib.check_status pyarrow.lib.ArrowNotImplementedError: Sequence converter for type dictionary<values=string, indices=int8, ordered=0> not implemented {noformat} -- This message was sent by Atlassian Jira (v8.3.4#803005)