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.

129 lines
5.8 KiB

8 years ago
  1. ![pybind11 logo](https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png)
  2. # pybind11 — Seamless operability between C++11 and Python
  3. [![Documentation Status](https://readthedocs.org/projects/pybind11/badge/?version=master)](http://pybind11.readthedocs.org/en/master/?badge=master)
  4. [![Documentation Status](https://readthedocs.org/projects/pybind11/badge/?version=stable)](http://pybind11.readthedocs.org/en/stable/?badge=stable)
  5. [![Gitter chat](https://img.shields.io/gitter/room/gitterHQ/gitter.svg)](https://gitter.im/pybind/Lobby)
  6. [![Build Status](https://travis-ci.org/pybind/pybind11.svg?branch=master)](https://travis-ci.org/pybind/pybind11)
  7. [![Build status](https://ci.appveyor.com/api/projects/status/riaj54pn4h08xy40?svg=true)](https://ci.appveyor.com/project/wjakob/pybind11)
  8. **pybind11** is a lightweight header-only library that exposes C++ types in Python
  9. and vice versa, mainly to create Python bindings of existing C++ code. Its
  10. goals and syntax are similar to the excellent
  11. [Boost.Python](http://www.boost.org/doc/libs/1_58_0/libs/python/doc/) library
  12. by David Abrahams: to minimize boilerplate code in traditional extension
  13. modules by inferring type information using compile-time introspection.
  14. The main issue with Boost.Python—and the reason for creating such a similar
  15. project—is Boost. Boost is an enormously large and complex suite of utility
  16. libraries that works with almost every C++ compiler in existence. This
  17. compatibility has its cost: arcane template tricks and workarounds are
  18. necessary to support the oldest and buggiest of compiler specimens. Now that
  19. C++11-compatible compilers are widely available, this heavy machinery has
  20. become an excessively large and unnecessary dependency.
  21. Think of this library as a tiny self-contained version of Boost.Python with
  22. everything stripped away that isn't relevant for binding generation. Without
  23. comments, the core header files only require ~4K lines of code and depend on
  24. Python (2.7 or 3.x, or PyPy2.7 >= 5.7) and the C++ standard library. This
  25. compact implementation was possible thanks to some of the new C++11 language
  26. features (specifically: tuples, lambda functions and variadic templates). Since
  27. its creation, this library has grown beyond Boost.Python in many ways, leading
  28. to dramatically simpler binding code in many common situations.
  29. Tutorial and reference documentation is provided at
  30. [http://pybind11.readthedocs.org/en/master](http://pybind11.readthedocs.org/en/master).
  31. A PDF version of the manual is available
  32. [here](https://media.readthedocs.org/pdf/pybind11/master/pybind11.pdf).
  33. ## Core features
  34. pybind11 can map the following core C++ features to Python
  35. - Functions accepting and returning custom data structures per value, reference, or pointer
  36. - Instance methods and static methods
  37. - Overloaded functions
  38. - Instance attributes and static attributes
  39. - Arbitrary exception types
  40. - Enumerations
  41. - Callbacks
  42. - Iterators and ranges
  43. - Custom operators
  44. - Single and multiple inheritance
  45. - STL data structures
  46. - Iterators and ranges
  47. - Smart pointers with reference counting like ``std::shared_ptr``
  48. - Internal references with correct reference counting
  49. - C++ classes with virtual (and pure virtual) methods can be extended in Python
  50. ## Goodies
  51. In addition to the core functionality, pybind11 provides some extra goodies:
  52. - Python 2.7, 3.x, and PyPy (PyPy2.7 >= 5.7) are supported with an
  53. implementation-agnostic interface.
  54. - It is possible to bind C++11 lambda functions with captured variables. The
  55. lambda capture data is stored inside the resulting Python function object.
  56. - pybind11 uses C++11 move constructors and move assignment operators whenever
  57. possible to efficiently transfer custom data types.
  58. - It's easy to expose the internal storage of custom data types through
  59. Pythons' buffer protocols. This is handy e.g. for fast conversion between
  60. C++ matrix classes like Eigen and NumPy without expensive copy operations.
  61. - pybind11 can automatically vectorize functions so that they are transparently
  62. applied to all entries of one or more NumPy array arguments.
  63. - Python's slice-based access and assignment operations can be supported with
  64. just a few lines of code.
  65. - Everything is contained in just a few header files; there is no need to link
  66. against any additional libraries.
  67. - Binaries are generally smaller by a factor of at least 2 compared to
  68. equivalent bindings generated by Boost.Python. A recent pybind11 conversion
  69. of PyRosetta, an enormous Boost.Python binding project,
  70. [reported](http://graylab.jhu.edu/RosettaCon2016/PyRosetta-4.pdf) a binary
  71. size reduction of **5.4x** and compile time reduction by **5.8x**.
  72. - When supported by the compiler, two new C++14 features (relaxed constexpr and
  73. return value deduction) are used to precompute function signatures at compile
  74. time, leading to smaller binaries.
  75. - With little extra effort, C++ types can be pickled and unpickled similar to
  76. regular Python objects.
  77. ## Supported compilers
  78. 1. Clang/LLVM 3.3 or newer (for Apple Xcode's clang, this is 5.0.0 or newer)
  79. 2. GCC 4.8 or newer
  80. 3. Microsoft Visual Studio 2015 Update 3 or newer
  81. 4. Intel C++ compiler 16 or newer (15 with a [workaround](https://github.com/pybind/pybind11/issues/276))
  82. 5. Cygwin/GCC (tested on 2.5.1)
  83. ## About
  84. This project was created by [Wenzel Jakob](http://rgl.epfl.ch/people/wjakob).
  85. Significant features and/or improvements to the code were contributed by
  86. Jonas Adler,
  87. Sylvain Corlay,
  88. Trent Houliston,
  89. Axel Huebl,
  90. @hulucc,
  91. Sergey Lyskov
  92. Johan Mabille,
  93. Tomasz Miąsko,
  94. Dean Moldovan,
  95. Ben Pritchard,
  96. Jason Rhinelander,
  97. Boris Schäling,
  98. Pim Schellart,
  99. Ivan Smirnov, and
  100. Patrick Stewart.
  101. ### License
  102. pybind11 is provided under a BSD-style license that can be found in the
  103. ``LICENSE`` file. By using, distributing, or contributing to this project,
  104. you agree to the terms and conditions of this license.