[ARROW-1450] [Python] Raise proper error if custom serialization handler fails

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.7.0
• Component/s: Python
• External issue URL: https://github.com/apache/arrow/issues/17470
• Assignee: Philipp Moritz
• Reporter: Philipp Moritz
• Created: 02/Sep/17 20:09
• Updated: 11/Jan/23 07:14
• Resolved: 03/Sep/17 19:11

Description

At the moment, the following fails:

def test_serializaton_callback_error():

    class TempClass(object):
            pass

    # Have a SerializationContext but TempClass is not
    # registered

    serialization_context = pa.SerializationContext()

    with pytest.raises(pa.SerializationCallbackError):
        serialized_object = pa.serialize(TempClass, serialization_context)

This is because serialize will raise a generic ArrowException instead of a SerializationCallbackError. We do need the latter because it contains the object that couldn't be serialized, which is important to give good error messages; in the case of Ray we sometimes want use the object to register additional serialization callbacks on the fly to make the user experience smoother.