Application-supplied message iterators are required to be iterators <http://www.grpc.io/grpc/python/_modules/grpc.html#StreamUnaryMultiCallable.__call__>. It is currently the case that when an application passes an object that is not an iterator <https://docs.python.org/2/library/stdtypes.html#iterator-types> of messages where one is required gRPC Python is not as helpful in handling the defect as it could be <https://github.com/grpc/grpc/issues/8231>, and we’re looking at remedying that <https://github.com/thunderboltsid/grpc/commit/f3031c3ccba62f0856c79844f673836dcdcb0cba>. Along the way, we’ve discovered that the current behavior of gRPC Python when passed an iterable of messages is to do what the application probably intended: populate the RPC’s request stream with the messages. The way we’ve currently drafted the change, gRPC Python instead would in the future detect this application-level type error and abort the RPC.
Is there anyone out there passing lists, tuples, or other iterables of request messages where the API requires an iterator of request messages? (Embarrassingly, we’ve made this mistake in our own tests.) If so, would it be onerous or undesirable to have to pass an iterator over the messages in the iterable rather than the iterable itself? There might be people out there who might be using this unguaranteed behaviour in production. Is this unguaranteed behaviour something that gRPC Python should start supporting formally, or may it be dropped? Since it would be trivial to support iterables with a single `iterator = iter(request_iterator_or_iterable)`, the question has nothing to do with implementation complexity or performance and boils down to whether we want to provide greater convenience to application developers at the cost of an increase in requirements placed on gRPC Python. Cheers, Sid -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To post to this group, send email to grpc-io@googlegroups.com. Visit this group at https://groups.google.com/group/grpc-io. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/83cf7763-39f1-44dc-8633-00f8a6f0d8d7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
