Hello, in the end I managed to fix this issue using CopyFrom(fds), where fds is an instnce of google.protobuf.descriptor_pb2.FileDescriptorSet, rather than file.append function as show in my original code.
So in the code above we would call my_proto_instance.descriptor_set.CopyFrom(addressbook_fds) instead of my_proto_instance.descriptor_set.file.append(addressbook_fds). Hope someone finds this useful. Cheers Jan On Friday, April 7, 2023 at 11:38:50 PM UTC+2 Jan Machek wrote: > Hello, > > I am trying to build self-describing messages using Python. I read through > the documentation > https://protobuf.dev/programming-guides/techniques/#self-description as > well as through the Python API > https://googleapis.dev/python/protobuf/latest/google/protobuf.html, but I > am still not very sure about how to do that. > > I started with the example message > syntax = "proto3"; import "google/protobuf/any.proto"; import > "google/protobuf/descriptor.proto"; message SelfDescribingMessage { // > Set of FileDescriptorProtos which describe the type and its dependencies. > google.protobuf.FileDescriptorSet descriptor_set = 1; // The message and > its type, encoded as an Any message. google.protobuf.Any message = 2; } > > And I would like to pass through it a simple addressbook message > > syntax = "proto2"; > > package tutorial; > > message AddressBook { > optional string name = 1; > optional string number = 2; > } > > The AddressBook message would be contained in the message field and the > descriptor_set field would contain the descriptor of the proto above. > > However I could not do this no matter what I have tried. > > The closest I got was exporting a file descriptor set from the > SelfDescribingMessage.proto given in the documentation as "protoc > --proto_path=. --proto_path=./include > --descriptor_set_out=./self_describing_ds --include_imports > self_describing.proto" and then reading it > > with open("self_describing_ds", 'rb') as fh: > fds = descriptor_pb2.FileDescriptorSet.FromString(fh.read()) > > message_classes = message_factory.GetMessages(fds.file) > my_proto_instance = message_classes["SelfDescribingMessage"]() > > address_book = addressbook_pb2.AddressBook() > address_book.name = "John Doe" > address_book.number = "123456" > > my_proto_instance.message.Pack(address_book) > > I am not able to set my_proto_instance.descriptor_set though. Extracting > address book descriptor set using protoc and then reading it and trying to > append it > > with open("addressbook_ds", 'rb') as fh: > addressbook_fds = > descriptor_pb2.FileDescriptorSet.FromString(fh.read()) > my_proto_instance.descriptor_set.file.append(addressbook_fds) > > fails on > > TypeError: Parameter to MergeFrom() must be instance of same class: > expected <class 'FileDescriptorProto'> got <class > 'google.protobuf.descriptor_pb2.FileDescriptorProto'>. > > I could not get any closer. > > Does anyone have any simple example on sending the self-describing > messages in Python, please? > > Thanks a lot in advance. > > Jan > > > > > -- You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To unsubscribe from this group and stop receiving emails from it, send an email to protobuf+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/protobuf/e85a4c87-9c2b-4a99-8c9c-a88db37a8b6cn%40googlegroups.com.
