README.md
1Protocol Buffers - Google's data interchange format
2===================================================
3
4Copyright 2008 Google Inc.
5
6This directory contains the Python Protocol Buffers runtime library.
7
8Normally, this directory comes as part of the protobuf package, available
9from:
10
11 https://developers.google.com/protocol-buffers/
12
13The complete package includes the C++ source code, which includes the
14Protocol Compiler (protoc). If you downloaded this package from PyPI
15or some other Python-specific source, you may have received only the
16Python part of the code. In this case, you will need to obtain the
17Protocol Compiler from some other source before you can use this
18package.
19
20Development Warning
21===================
22
23The pure python performance is slow. For better performance please
24use python c++ implementation.
25
26Installation
27============
28
291) Make sure you have Python 3.7 or newer. If in doubt, run:
30
31 $ python -V
32
332) If you do not have setuptools installed, note that it will be
34 downloaded and installed automatically as soon as you run `setup.py`.
35 If you would rather install it manually, you may do so by following
36 the instructions on [this page](https://packaging.python.org/en/latest/installing.html#setup-for-installing-packages).
37
383) Build the C++ code, or install a binary distribution of `protoc`. If
39 you install a binary distribution, make sure that it is the same
40 version as this package. If in doubt, run:
41
42 $ protoc --version
43
444) Build and run the tests:
45
46 $ python setup.py build
47 $ python setup.py test
48
49 To build, test, and use the C++ implementation, you must first compile
50 `libprotobuf.so`:
51
52 $ (cd .. && make)
53
54 On OS X:
55
56 If you are running a Homebrew-provided Python, you must make sure another
57 version of protobuf is not already installed, as Homebrew's Python will
58 search `/usr/local/lib` for `libprotobuf.so` before it searches
59 `../src/.libs`.
60
61 You can either unlink Homebrew's protobuf or install the `libprotobuf` you
62 built earlier:
63
64 $ brew unlink protobuf
65
66 or
67
68 $ (cd .. && make install)
69
70 On other *nix:
71
72 You must make `libprotobuf.so` dynamically available. You can either
73 install libprotobuf you built earlier, or set `LD_LIBRARY_PATH`:
74
75 $ export LD_LIBRARY_PATH=../src/.libs
76
77 or
78
79 $ (cd .. && make install)
80
81 To build the C++ implementation run:
82
83 $ python setup.py build --cpp_implementation
84
85 Then run the tests like so:
86
87 $ python setup.py test --cpp_implementation
88
89 If some tests fail, this library may not work correctly on your
90 system. Continue at your own risk.
91
92 Please note that there is a known problem with some versions of
93 Python on Cygwin which causes the tests to fail after printing the
94 error: `sem_init: Resource temporarily unavailable`. This appears
95 to be a [bug either in Cygwin or in
96 Python](http://www.cygwin.com/ml/cygwin/2005-07/msg01378.html).
97
98 We do not know if or when it might be fixed. We also do not know
99 how likely it is that this bug will affect users in practice.
100
1015) Install:
102
103 $ python setup.py install
104
105 or:
106
107 $ (cd .. && make install)
108 $ python setup.py install --cpp_implementation
109
110 This step may require superuser privileges.
111 NOTE: To use C++ implementation, you need to export an environment
112 variable before running your program. See the "C++ Implementation"
113 section below for more details.
114
115Usage
116=====
117
118The complete documentation for Protocol Buffers is available via the
119web at:
120
121 https://developers.google.com/protocol-buffers/
122
123C++ Implementation
124==================
125
126The C++ implementation for Python messages is built as a Python extension to
127improve the overall protobuf Python performance.
128
129To use the C++ implementation, you need to install the C++ protobuf runtime
130library, please see instructions in the parent directory.
131