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Rok Mihevc commented on ARROW-4832: ----------------------------------- This issue has been migrated to [issue #21347|https://github.com/apache/arrow/issues/21347] on GitHub. Please see the [migration documentation|https://github.com/apache/arrow/issues/14542] for further details. > [Python] pandas Index metadata for RangeIndex is incorrect > ---------------------------------------------------------- > > Key: ARROW-4832 > URL: https://issues.apache.org/jira/browse/ARROW-4832 > Project: Apache Arrow > Issue Type: Bug > Components: Python > Reporter: Wes McKinney > Priority: Major > Fix For: 0.14.0 > > > I'm looking at ARROW-1639 to optimize storage and loading of RangeIndex, but > in the meantime I wanted to report this oddness: > {code} > In [9]: df = pd.DataFrame({'a': [1, 2, 3]}) > > In [10]: json.loads(pa.Table.from_pandas(df).schema.metadata[b'pandas']) > > Out[10]: > {'index_columns': ['__index_level_0__'], > 'column_indexes': [{'name': None, > 'field_name': None, > 'pandas_type': 'unicode', > 'numpy_type': 'object', > 'metadata': {'encoding': 'UTF-8'}}], > 'columns': [{'name': 'a', > 'field_name': 'a', > 'pandas_type': 'int64', > 'numpy_type': 'int64', > 'metadata': None}, > {'name': None, > 'field_name': '__index_level_0__', > 'pandas_type': 'int64', > 'numpy_type': 'int64', > 'metadata': None}], > 'pandas_version': '0.23.4'} > {code} -- This message was sent by Atlassian Jira (v8.20.10#820010)