Github user viirya commented on a diff in the pull request:
https://github.com/apache/spark/pull/22610#discussion_r223217704
--- Diff: python/pyspark/sql/functions.py ---
@@ -2909,6 +2909,12 @@ def pandas_udf(f=None, returnType=None,
functionType=None):
can fail on special rows, the workaround is to incorporate the
condition into the functions.
.. note:: The user-defined functions do not take keyword arguments on
the calling side.
+
+ .. note:: The data type of returned `pandas.Series` from the
user-defined functions should be
+ matched with defined returnType (see :meth:`types.to_arrow_type`
and
+ :meth:`types.from_arrow_type`). When there is mismatch between
them, Spark might do
+ conversion on returned data. The conversion is not guaranteed to
be correct and results
+ should be checked for accuracy by users.
--- End diff --
Yeah, I agreed. If there is next upgrade of PyArrow available, we may be
able to provide the option to raise error when an unsafe cast.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
