zhengruifeng commented on code in PR #42798:
URL: https://github.com/apache/spark/pull/42798#discussion_r1315417026
##########
python/pyspark/pandas/groupby.py:
##########
@@ -3534,7 +3534,12 @@ def _reduce_for_stat_function(
for label in psdf._internal.column_labels:
psser = psdf._psser_for(label)
input_scol = psser._dtype_op.nan_to_null(psser).spark.column
- output_scol = sfun(input_scol)
+ if sfun.__name__ == "sum" and isinstance(
+ psdf._internal.spark_type_for(label), StringType
+ ):
+ output_scol = F.concat_ws("", F.collect_list(input_scol))
Review Comment:
since string columns are computed together with numerical ones, I think we
have to compute strings' sum in an aggregation way:
```
F.concat_ws("", F.array_sort(
F.collect_list(F.struct(NATURAL_ORDER_COLUMN_NAME, input_scol))
)
```
For struct type, array_sort sort elements by first field then second field,
IIRC
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
