Installing Cython¶

Many scientific Python distributions, such as Anaconda [Anaconda], Enthought Canopy [Canopy], and Sage [Sage], bundle Cython and no setup is needed. Note however that if your distribution ships a version of Cython which is too old you can still use the instructions below to update Cython.

Unlike most Python software, Cython requires a C compiler to be present on the system. The details of getting a C compiler varies according to the system used:

  • Linux The GNU C Compiler (gcc) is usually present, or easily available through the package system. On Ubuntu or Debian, for instance, it is part of the build-essential package. Next to a C compiler, Cython requires the Python header files. On Ubuntu or Debian, the command sudo apt-get install build-essential python3-dev will fetch everything you need.

  • Mac OS X To retrieve gcc, one option is to install Apple’s XCode, which can be retrieved from the Mac OS X’s install DVDs or from https://developer.apple.com/.

  • Windows The CPython project recommends building extension modules (including Cython modules) with the same compiler that Python was built with. This is usually a specific version of Microsoft Visual C/C++ (MSVC) - see https://wiki.python.org/moin/WindowsCompilers. MSVC is the only compiler that Cython is currently tested with on Windows. If you’re having difficulty making setuptools detect MSVC then PyMSVC aims to solve this.

    A possible alternative is the open source MinGW (a Windows distribution of gcc). See the appendix for instructions for setting up MinGW manually. Enthought Canopy and Python(x,y) bundle MinGW, but some of the configuration steps in the appendix might still be necessary.

The simplest way of installing Cython is by using pip:

pip install Cython

The newest Cython release can always be downloaded from https://cython.org/. Unpack the tarball or zip file, enter the directory, and then run:

python setup.py install

For one-time builds, e.g. for CI/testing, on platforms that are not covered by one of the wheel packages provided on PyPI, it is substantially faster than a full source build to install an uncompiled (slower) version of Cython with

pip install Cython --install-option="--no-cython-compile"
Anaconda

https://docs.anaconda.com/anaconda/

Canopy

https://www.enthought.com/product/canopy/

Sage

  1. Stein et al., Sage Mathematics Software, https://www.sagemath.org/