saavannanavati commented on a change in pull request #12352:
URL: https://github.com/apache/beam/pull/12352#discussion_r466145176
##########
File path: sdks/python/apache_beam/runners/common.py
##########
@@ -1340,6 +1342,17 @@ def process_outputs(
self.per_element_output_counter.add_input(0)
return
+ if isinstance(results, (dict, str, unicode, bytes)):
+ results_type = type(results).__name__
+ raise TypeCheckError(
+ 'Returning a %s from a ParDo or FlatMap is '
+ 'discouraged. Please use list("%s") if you really '
+ 'want this behavior.' % (results_type, results))
+ elif not isinstance(results, collections.Iterable):
Review comment:
Why is this check slow? Also, if we remove it, how should we give the
user the relevant error message?
----------------------------------------------------------------
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.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
