Created 10 February 2004, last updated 19 November 2021 An older version of this document is also available in Russian. Cog is a file generation tool. It lets you use pieces of Python code as generators in your source files to generate whatever text you need. This page describes version 3.3.0, released November 19, 2021. The sections below are: What does it do?DesignInstallationWriting the source