GitHub user viirya opened a pull request: https://github.com/apache/spark/pull/16115
[SPARK-18667][PySpark][SQL] Change the way to group row in BatchEvalPythonExec so input_file_name function can work with UDF in pyspark ## What changes were proposed in this pull request? `input_file_name` doesn't return filename when working with UDF in PySpark. An example shows the problem: from pyspark.sql.functions import * from pyspark.sql.types import * def filename(path): return path sourceFile = udf(filename, StringType()) spark.read.json("tmp.json").select(sourceFile(input_file_name())).show() +---------------------------+ |filename(input_file_name())| +---------------------------+ | | +---------------------------+ The cause of this issue is, we group rows in `BatchEvalPythonExec` for batching processing of PythonUDF. Currently we group rows first and then evaluate expressions on the rows. If the data is less than the required number of rows for a group, the iterator will be consumed to the end before the evaluation. However, once the iterator reaches the end, we will unset input filename. So the input_file_name expression can't return correct filename. This patch fixes the approach to group the batch of rows. We evaluate the expression first and then group evaluated results to batch. ## How was this patch tested? Added unit test to PySpark. Please review http://spark.apache.org/contributing.html before opening a pull request. You can merge this pull request into a Git repository by running: $ git pull https://github.com/viirya/spark-1 fix-py-udf-input-filename Alternatively you can review and apply these changes as the patch at: https://github.com/apache/spark/pull/16115.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #16115 ---- commit 7cd606b6605ac75f311dca2cff988f20ba0ad7a0 Author: Liang-Chi Hsieh <vii...@gmail.com> Date: 2016-12-02T05:50:47Z Change the way to group row in BatchEvalPythonExec so udf works with input_file_name in pyspark. ---- --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. --- --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org