Registry

A Registry is a collection of descriptors that enables lookup by name. It is only needed when working with google.protobuf.Any or extensions in ProtoJSON; everywhere else, descriptors are self-contained.

Creating a registry

Pass file descriptors (or message/enum types) to the constructor:

from protobuf import Registry
from gen import example_pb

registry = Registry(example_pb.desc())

Or build one incrementally with add():

registry = Registry()
registry.add(example_pb.desc())

Looking up types

registry.message("example.User")         # DescMessage | None
registry.enum("example.PhoneType")       # DescEnum | None
registry.file("example.proto")           # DescFile | None
registry.extension("example.sensitive")  # DescExtension | None

Using a registry with Any and JSON

Pass the registry when serializing or deserializing messages that contain google.protobuf.Any fields or extensions. See Any and Extensions and JSON for examples.

Iterating over fields

Iterating over a message yields the DescField of each currently set field; see Working with Messages for details. The registry pairs naturally with message iteration to build generic tools (serializers, validators, diff tools) that operate on any message type without knowing the concrete type at compile time.