Welcome to Cython’s Documentation

Also see the Cython project homepage.

• Getting Started
  • Cython - an overview
  • Installing Cython
  • Building Cython code
  • Faster code via static typing
• Tutorials
  • Basic Tutorial
  • Calling C functions
  • Using C libraries
  • Extension types (aka. cdef classes)
  • pxd files
  • Caveats
  • Profiling
  • Unicode and passing strings
  • Memory Allocation
  • Embedding Cython modules in C/C++ applications
  • Pure Python Mode
  • Working with NumPy
  • Working with Python arrays
  • Writing parallel code with Cython
  • Further reading
  • Related work
  • Appendix: Installing MinGW on Windows
• Users Guide
  • Language Basics
  • Extension Types
  • Special Methods of Extension Types
  • Sharing Declarations Between Cython Modules
  • Interfacing with External C Code
  • Source Files and Compilation
  • Early Binding for Speed
  • Using C++ in Cython
  • Fused Types (Templates)
  • Porting Cython code to PyPy
  • The Limited API and Stable ABI
  • Migrating from Cython 0.29 to 3.0
  • Limitations
  • Differences between Cython and Pyrex
  • Typed Memoryviews
  • Implementing the buffer protocol
  • Using Parallelism
  • Debugging your Cython program
  • Cython for NumPy users
  • Creating Numpy ufuncs
  • Pythran as a Numpy backend
  • Cython and the GIL
  • Free threading
  • Tempita templating language
  • Troubleshooting
  • FAQ
  • Indices and tables
• Glossary
• Reference Guide
  • Compilation
  • Indices and tables
• Contributing
  • Bug/Feature Tracking and Project Culture
  • Getting started working on Cython
  • “Where does that C code come from?”
  • Cython internals
  • The Test Suite
• Cython Changelog
  • 3.3.0a1 (2026-??-??)
  • 3.2.4 (2026-01-04)
  • 3.2.3 (2025-12-14)
  • 3.2.2 (2025-11-30)
  • 3.2.1 (2025-11-12)
  • 3.2.0 (2025-11-05)
  • 3.2.0b3 (2025-10-30)
  • 3.2.0b2 (2025-10-27)
  • 3.2.0b1 (2025-10-22)
  • 3.1.8 (2026-01-03)
  • 3.1.7 (2025-11-12)
  • 3.1.6 (2025-10-23)
  • 3.1.5 (2025-10-20)
  • 3.1.4 (2025-09-16)
  • 3.1.3 (2025-08-13)
  • 3.1.2 (2025-06-09)
  • 3.1.1 (2025-05-19)
  • 3.1.0 (2025-05-08)
  • 3.1.0 rc 2 (2025-05-07)
  • 3.1.0 rc 1 (2025-05-01)
  • 3.1.0 beta 1 (2025-04-03)
  • 3.1.0 alpha 1 (2024-11-08)
  • 3.0.12 (2025-02-11)
  • 3.0.11 (2024-08-05)
  • 3.0.10 (2024-03-30)
  • 3.0.9 (2024-03-05)
  • 3.0.8 (2024-01-10)
  • 3.0.7 (2023-12-19)
  • 3.0.6 (2023-11-26)
  • 3.0.5 (2023-10-31)
  • 3.0.4 (2023-10-17)
  • 3.0.3 (2023-10-05)
  • 3.0.2 (2023-08-27)
  • 3.0.1 (2023-08-25)
  • 3.0.0 unified release notes
  • Major themes in 3.0.0
  • 3.0.0 (2023-07-17)
  • 3.0.0 rc 2 (2023-07-13)
  • 3.0.0 rc 1 (2023-07-12)
  • 3.0.0 beta 3 (2023-05-24)
  • 3.0.0 beta 2 (2023-03-27)
  • 3.0.0 beta 1 (2023-02-25)
  • 3.0.0 alpha 11 (2022-07-31)
  • 3.0.0 alpha 10 (2022-01-06)
  • 3.0.0 alpha 9 (2021-07-21)
  • 3.0.0 alpha 8 (2021-07-02)
  • 3.0.0 alpha 7 (2021-05-24)
  • 3.0.0 alpha 6 (2020-07-31)
  • 3.0.0 alpha 5 (2020-05-19)
  • 3.0.0 alpha 4 (2020-05-05)
  • 3.0.0 alpha 3 (2020-04-27)
  • 3.0.0 alpha 2 (2020-04-23)
  • 3.0.0 alpha 1 (2020-04-12)
  • 0.29.37 (2023-12-18)
  • 0.29.36 (2023-07-04)
  • 0.29.35 (2023-05-24)
  • 0.29.34 (2023-04-02)
  • 0.29.33 (2023-01-06)
  • 0.29.32 (2022-07-29)
  • 0.29.31 (2022-07-27)
  • 0.29.30 (2022-05-16)
  • 0.29.29 (2022-05-16)
  • 0.29.28 (2022-02-17)
  • 0.29.27 (2022-01-28)
  • 0.29.26 (2021-12-16)
  • 0.29.25 (2021-12-06)
  • 0.29.24 (2021-07-14)
  • 0.29.23 (2021-04-14)
  • 0.29.22 (2021-02-20)
  • 0.29.21 (2020-07-09)
  • 0.29.20 (2020-06-10)
  • 0.29.19 (2020-05-20)
  • 0.29.18 (2020-05-18)
  • 0.29.17 (2020-04-26)
  • 0.29.16 (2020-03-24)
  • 0.29.15 (2020-02-06)
  • 0.29.14 (2019-11-01)
  • 0.29.13 (2019-07-26)
  • 0.29.12 (2019-07-07)
  • 0.29.11 (2019-06-30)
  • 0.29.10 (2019-06-02)
  • 0.29.9 (2019-05-29)
  • 0.29.8 (2019-05-28)
  • 0.29.7 (2019-04-14)
  • 0.29.6 (2019-02-27)
  • 0.29.5 (2019-02-09)
  • 0.29.4 (2019-02-01)
  • 0.29.3 (2019-01-19)
  • 0.29.2 (2018-12-14)
  • 0.29.1 (2018-11-24)
  • 0.29 (2018-10-14)
  • 0.28.6 (2018-11-01)
  • 0.28.5 (2018-08-03)
  • 0.28.4 (2018-07-08)
  • 0.28.3 (2018-05-27)
  • 0.28.2 (2018-04-13)
  • 0.28.1 (2018-03-18)
  • 0.28 (2018-03-13)
  • 0.27.3 (2017-11-03)
  • 0.27.2 (2017-10-22)
  • 0.27.1 (2017-10-01)
  • 0.27 (2017-09-23)
  • 0.26.1 (2017-08-29)
  • 0.26 (2017-07-19)
  • 0.25.2 (2016-12-08)
  • 0.25.1 (2016-10-26)
  • 0.25 (2016-10-25)
  • 0.24.1 (2016-07-15)
  • 0.24 (2016-04-04)
  • 0.23.5 (2016-03-26)
  • 0.23.4 (2015-10-10)
  • 0.23.3 (2015-09-29)
  • 0.23.2 (2015-09-11)
  • 0.23.1 (2015-08-22)
  • 0.23 (2015-08-08)
  • 0.22.1 (2015-06-20)
  • 0.22 (2015-02-11)
  • 0.21.2 (2014-12-27)
  • 0.21.1 (2014-10-18)
  • 0.21 (2014-09-10)
  • 0.20.2 (2014-06-16)
  • 0.20.1 (2014-02-11)
  • 0.20 (2014-01-18)
  • 0.19.2 (2013-10-13)
  • 0.19.1 (2013-05-11)
  • 0.19 (2013-04-19)
  • 0.18 (2013-01-28)
  • 0.17.4 (2013-01-03)
  • 0.17.3 (2012-12-14)
  • 0.17.2 (2012-11-20)
  • 0.17.1 (2012-09-26)
  • 0.17 (2012-09-01)
  • 0.16 (2012-04-21)
  • 0.15.1 (2011-09-19)
  • 0.15 (2011-08-05)
  • 0.14.1 (2011-02-04)
  • 0.14 (2010-12-14)
  • 0.13 (2010-08-25)
  • 0.12.1 (2010-02-02)
  • 0.12 (2009-11-23)
  • 0.11.2 (2009-05-20)