Building Python extensions on Windows can be challenging due to the lack of a native compiler. However, with the right tools and configuration, you can successfully build and install Python extensions. In this tutorial, we will explore the steps required to build Python extensions on Windows.
Introduction to Python Extensions
Python extensions are libraries that provide additional functionality to the Python programming language. They are typically written in C or C++ and compiled into a dynamic link library (DLL) that can be imported into Python. To build Python extensions, you need a compiler that can generate code compatible with the Python interpreter.
Installing a Compiler
On Windows, the most commonly used compilers for building Python extensions are:
- Microsoft Visual Studio
- MinGW
Microsoft Visual Studio is a commercial integrated development environment (IDE) that includes a compiler. MinGW, on the other hand, is a free and open-source compiler that can be used to build Windows applications.
To install MinGW, download the installer from the official website and follow the installation instructions. Make sure to add the MinGW bin directory to your system’s PATH environment variable.
Configuring Distutils
Distutils is a Python module that provides a way to build and distribute Python packages. To configure Distutils to use the MinGW compiler, you need to create a distutils.cfg file in the Lib\distutils directory of your Python installation.
The distutils.cfg file should contain the following lines:
[build]
compiler=mingw32
This tells Distutils to use the MinGW compiler when building extensions.
Building and Installing Extensions
Once you have installed a compiler and configured Distutils, you can build and install Python extensions using the setup.py script. The setup.py script is typically included with the extension package and contains instructions for building and installing the extension.
To build and install an extension, navigate to the directory containing the setup.py script and run the following command:
python setup.py install
This will build the extension using the configured compiler and install it in your Python environment.
Alternative: Pre-Compiled Extensions
If you don’t want to build extensions from source, you can use pre-compiled extensions available from third-party websites. One popular website that provides pre-compiled extensions is http://www.lfd.uci.edu/~gohlke/pythonlibs/.
To install a pre-compiled extension, download the corresponding wheel file and use pip to install it:
pip install filename.whl
Make sure to replace filename.whl with the actual name of the wheel file.
Conclusion
Building Python extensions on Windows can be challenging, but with the right tools and configuration, you can successfully build and install extensions. By installing a compiler, configuring Distutils, and using the setup.py script, you can build and install extensions from source. Alternatively, you can use pre-compiled extensions available from third-party websites.