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Antoine Pitrou commented on ARROW-16611: ---------------------------------------- Hmm, where does the "java.lang.RuntimeException" come from? > [Python] MapArray pandas round trip is broken > --------------------------------------------- > > Key: ARROW-16611 > URL: https://issues.apache.org/jira/browse/ARROW-16611 > Project: Apache Arrow > Issue Type: Bug > Components: Python > Affects Versions: 8.0.0 > Reporter: Robbie Gruener > Priority: Major > > pyarrow.MapArray when converted to pandas cannot be successfully converted > back. > The following snipper does not work: > > ``` > import pyarrow as pa > data = [[('x', 1), ('y', 0)], [('a', 2), ('b', 45)]] > ty = pa.map_(pa.string(), pa.int64()) > map_col = pa.array(data, type=ty) > pa.MapArray.from_pandas(map_col.to_pandas()) > ``` > `Uncaught exception: ArrowTypeError: Expected bytes, got a 'int' object > (java.lang.RuntimeException)` -- This message was sent by Atlassian Jira (v8.20.7#820007)