bump2version is a maintained fork of the excellent bumpversion project.

Version-bump your software with a single command!

A small command line tool to simplify releasing software by updating all version
strings in your source code by the correct increment. Also creates commits and
tags:
- version formats are highly configurable
- works without any VCS, but happily reads tag information from and writes
  commits and tags to Git and Mercurial if available
- just handles text files, so it's not specific to any programming language
- supports Python 3 and PyPy3