Protocol Buffers - Google's data interchange format (grpc依赖) https://developers.google.com/protocol-buffers/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
Mike Kruskal fc048f4fe3 Add a conformance test for invalid end group tag. 1 month ago
..
dist Add Python 3.13 test coverage 2 months ago
docs
google Use ABSL_PREDICT_TRUE|FALSE instead of PROTOBUF_PREDICT_TRUE|FALSE. 1 month ago
pb_unit_tests Breaking change: Remove deprecated GetDebugString() from protobuf python cpp extension. 1 month ago
protobuf_distutils Add Python 3.13 test coverage 2 months ago
.repo-metadata.json
BUILD.bazel Migrated upb to use Copybara-standard stripping. 4 months ago
MANIFEST.in
README.md
build_targets.bzl Add a conformance test for invalid end group tag. 1 month ago
convert.c Setup fix for python/upb for the enforcement of closed enums in editions. 3 months ago
convert.h
descriptor.c Fix packed reflection handling bug in edition 2023. 3 months ago
descriptor.h
descriptor_containers.c
descriptor_containers.h
descriptor_pool.c
descriptor_pool.h
extension_dict.c
extension_dict.h
internal.bzl Load Python rules everywhere in protobuf 2 months ago
map.c Fixed a couple of compiler warnings. 6 months ago
map.h
message.c Fix signature of `PyUpb_MessageMeta_Clear` (#17959) 3 months ago
message.h
minimal_test.py
protobuf.c Migrated upb to use Copybara-standard stripping. 4 months ago
protobuf.h Migrated upb to use Copybara-standard stripping. 4 months ago
py_extension.bzl Load Python rules everywhere in protobuf 2 months ago
python_api.h
python_version_test.py
repeated.c
repeated.h
requirements.txt Add Python 3.13 test coverage 2 months ago
unknown_fields.c
unknown_fields.h
version_script.lds

README.md

Protocol Buffers Python

This directory contains the Protobuf library for Python.

For user documentation about how to use Protobuf Python, see https://protobuf.dev/getting-started/pythontutorial/

Installation

In most cases you should install the library using pip or another package manager:

$ pip install protobuf

The packages released on https://pypi.org/project/protobuf/#files include both a source distribution and binary wheels.

Building packages from this repo

If for some reason you wish to build the packages directly from this repo, you can use the following Bazel commands:

$ bazel build //python/dist:source_wheel
$ bazel build //python/dist:binary_wheel

The binary wheel will build against whatever version of Python is installed on your system. The source package is always the same and does not depend on a local version of Python.

Building from setup.py

We support building from setup.py, but only from a Python source package. You cannot build from setup.py using the GitHub repo or the GitHub source tarball.

To build a source package from this repo, see the instructions in the previous section.

Implementation backends

There are three separate implementations of Python Protobuf. All of them offer the same API and are thus functionally the same, though they have very different performance characteristics.

The runtime library contains a switching layer that can choose between these backends at runtime. Normally it will choose between them automatically, using priority-ordered list, and skipping any backends that are not available. However you can request a specific backend by setting the PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION environment variable to one of the following values:

  1. upb: Built on the upb C library, this is a new extension module released in 4.21.0. It offers better performance than any of the previous backends, and it is now the default. It is distributed in our PyPI packages, and requires no special installation. The code for this module lives in this directory.
  2. cpp: This extension module wraps the C++ protobuf library. It is deprecated and is no longer released in our PyPI packages, however it is still used in some legacy cases where apps want to perform zero-copy message sharing between Python and C++. It must be installed separately before it can be used. The code for this module lives in google/protobuf/pyext.
  3. python: The pure-Python backend, this does not require any extension module to be present on the system. The code for the pure-Python backend lives in google/protobuf/internal

The order given above is the general priority order, with upb being preferred the most and the python backend preferred the least. However this ordering can be overridden by the presence of a google.protobuf.internal._api_implementation module. See the logic in api_implementation.py for details.

You can check which backend you are using with the following snippet:

$ python
Python 3.10.9 (main, Dec  7 2022, 13:47:07) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from google.protobuf.internal import api_implementation
>>> print(api_implementation.Type())
upb

This is not an officially-supported or stable API, but it is useful for ad hoc diagnostics.

More information about sharing messages between Python and C++ is available here: https://protobuf.dev/reference/python/python-generated/#sharing-messages

Code generator

The code for the Protobuf Python code generator lives in //src/google/protobuf/compiler/python. The code generator can output two different files for each proto foo.proto:

  • foo_pb2.py: The module you import to actually use the protos.
  • foo_pb2.pyi: A stub file that describes the interface of the protos.

The foo_pb2.pyi file is useful for IDEs or for users who want to read the output file. The foo_pb2.py file is optimized for fast loading and is not readable at all.

Note that the pyi file is only generated if you pass the pyi_out option to protoc:

$ protoc --python_out=pyi_out:output_dir