[Python] Conversion from pandas of empty categorical fails with ArrowInvalid

[asfimport]

The conversion of an empty pandas categorical raises an exception. Before version 0.9.0 this was possible

import pandas as pd
import pyarrow as pa
pa.Table.from_pandas(pd.DataFrame({'cat': pd.Categorical([])}))

raises:

ArrowInvalid: Dictionary indices must have non-zero length

Reporter: Florian Jetter / @fjetter
Assignee: Uwe Korn / @xhochy

PRs and other links:

• GitHub Pull Request #1906

_{Note: This issue was originally created as ARROW-2443. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 1906
#1906