The setup.cfg file contains default options for commands of the setup.py script. This is very useful if the process for building and distributing the package is more complex and requires many optional arguments to be passed to the setup.py script commands. This setup.cfg file allows you to store such default parameters together with your source code on a per project basis. This will make your distribution flow independent from the project and also provides transparency about how your package was built/distributed to the users and other team members.
The syntax for the setup.cfg file is the same as provided by the built-in configparser module so it is similar to the popular Microsoft Windows INI files. Here is an example of the setup.cfg configuration file that provides some global, sdist, and bdist_wheel commands' defaults:
[global] quiet=1 [sdist] formats=zip,tar [bdist_wheel] universal=1
This example configuration will ensure that source distributions (sdist section) will always be created in two formats (ZIP and TAR) and the built wheel distributions (bdist_wheel section) will be created as universal wheels that are independent from the Python version. Also most of the output will be suppressed on every command by the global --quiet switch. Note that this option is included here only for demonstration purposes and it may not be a reasonable choice to suppress the output for every command by default.