Compile-time control determines whether fields of a message type are assigned the default value of an empty message instead of None.

[molanp]

Summary

Compile-time control determines whether fields of a message type are assigned the default value of an empty message instead of None.

What is the feature request for?

The core library

The Problem

The document mentions

When a field is a message, its presence is always tracked explicitly even if it is not marked as optional. Marking a message field as optional has no effect: the default value of such a field is always None, not an empty message.

Is it possible to control this behavior at compile time?

Compile-time control determines whether fields of a message type are assigned the default value of an empty message instead of None.
If this behavior can be controlled when compiling into a .py file, then it's unnecessary to manually initialize each message field when using it.

This definition file serves as an example.

syntax = "proto3";

message Req {
  message DataReq {
    int64 field_one = 4;
  }
  DataReq data = 1;
}

You can do this with the fields in the data.

req = Req()
req.data.field_one = 7

Instead

req = Req()
req.data = DataReq()
req.data.field_one = 7

The Ideal Solution

This behavior can be controlled using parameters at compile time.

The Current Solution

No response