How to access unknown fields
I am working with a large number of message types with similar but not identical structure. All the stuff that's common among these is in another message. When a message comes in, I parse it using the common message type. However, I can't seem to find a way to access the fields outside of this type (ie the non-common fields). Is there a way to access the unknown field set in python?
Edit: I just saw this in the documentation:
"If a message has unknown fields, the current Java and C++ implementations write them in arbitrary order after the sequentially-ordered known fields. The current Python implementation does not track unknown fields."
Does this mean that if I parse using the common type, eg:
proto = msg_pb2.Common() proto.ParseFromString(raw_msg)
Any fields not defined in message Common are thrown away?
To someone looking for an answer to this, the reflection module helped me: https://developers.google.com/protocol-buffers/docs/reference/python/google.protobuf.reflection-module
The relevant sample code:
Sample usage:
file_descriptor = descriptor_pb2.FileDescriptorProto()
file_descriptor.ParseFromString(proto2_string)
msg_descriptor = descriptor.MakeDescriptor(file_descriptor.message_type[0])
msg_class = reflection.MakeClass(msg_descriptor)
msg = msg_class()
Args:
descriptor: A descriptor.Descriptor object describing the protobuf.
Returns:
The Message class object described by the descriptor.
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