README.md
1Protocol Buffers - Google's data interchange format
2===================================================
3
4[](https://travis-ci.org/google/protobuf)
5
6Copyright 2008 Google Inc.
7
8This directory contains the Python Protocol Buffers runtime library.
9
10Normally, this directory comes as part of the protobuf package, available
11from:
12
13 https://developers.google.com/protocol-buffers/
14
15The complete package includes the C++ source code, which includes the
16Protocol Compiler (protoc). If you downloaded this package from PyPI
17or some other Python-specific source, you may have received only the
18Python part of the code. In this case, you will need to obtain the
19Protocol Compiler from some other source before you can use this
20package.
21
22Development Warning
23===================
24
25The Python implementation of Protocol Buffers is not as mature as the C++
26and Java implementations. It may be more buggy, and it is known to be
27pretty slow at this time. If you would like to help fix these issues,
28join the Protocol Buffers discussion list and let us know!
29
30Installation
31============
32
331) Make sure you have Python 2.6 or newer. If in doubt, run:
34
35 $ python -V
36
372) If you do not have setuptools installed, note that it will be
38 downloaded and installed automatically as soon as you run setup.py.
39 If you would rather install it manually, you may do so by following
40 the instructions on this page:
41
42 https://packaging.python.org/en/latest/installing.html#setup-for-installing-packages
43
443) Build the C++ code, or install a binary distribution of protoc. If
45 you install a binary distribution, make sure that it is the same
46 version as this package. If in doubt, run:
47
48 $ protoc --version
49
504) Build and run the tests:
51
52 $ python setup.py build
53 $ python setup.py test
54
55 To build, test, and use the C++ implementation, you must first compile
56 libprotobuf.so:
57
58 $ (cd .. && make)
59
60 On OS X:
61
62 If you are running a homebrew-provided python, you must make sure another
63 version of protobuf is not already installed, as homebrew's python will
64 search /usr/local/lib for libprotobuf.so before it searches ../src/.libs
65 You can either unlink homebrew's protobuf or install the libprotobuf you
66 built earlier:
67
68 $ brew unlink protobuf
69 or
70 $ (cd .. && make install)
71
72 On other *nix:
73
74 You must make libprotobuf.so dynamically available. You can either
75 install libprotobuf you built earlier, or set LD_LIBRARY_PATH:
76
77 $ export LD_LIBRARY_PATH=../src/.libs
78 or
79 $ (cd .. && make install)
80
81 To build the C++ implementation run:
82 $ python setup.py build --cpp_implementation
83
84 Then run the tests like so:
85 $ python setup.py test --cpp_implementation
86
87 If some tests fail, this library may not work correctly on your
88 system. Continue at your own risk.
89
90 Please note that there is a known problem with some versions of
91 Python on Cygwin which causes the tests to fail after printing the
92 error: "sem_init: Resource temporarily unavailable". This appears
93 to be a bug either in Cygwin or in Python:
94 http://www.cygwin.com/ml/cygwin/2005-07/msg01378.html
95 We do not know if or when it might me fixed. We also do not know
96 how likely it is that this bug will affect users in practice.
97
985) Install:
99
100 $ python setup.py install
101
102 or:
103
104 $ (cd .. && make install)
105 $ python setup.py install --cpp_implementation
106
107 This step may require superuser privileges.
108 NOTE: To use C++ implementation, you need to export an environment
109 variable before running your program. See the "C++ Implementation"
110 section below for more details.
111
112Usage
113=====
114
115The complete documentation for Protocol Buffers is available via the
116web at:
117
118 https://developers.google.com/protocol-buffers/
119
120C++ Implementation
121==================
122
123The C++ implementation for Python messages is built as a Python extension to
124improve the overall protobuf Python performance.
125
126To use the C++ implementation, you need to install the C++ protobuf runtime
127library, please see instructions in the parent directory.
128
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