This is a Homebrew tap for dmgbuild, a tool for automating the creation of OS X disk images.
Although it does have somewhat of a library feature, dmgbuild is primarily an application written in Python. I personally believe that dmgbuild has the potential to reach a much wider audience, with one caveat: non-Python developers don't want to install dmgbuild via pip. They don't have a Python environment set up, and don't care to have to do so for one tool. However, Homebrew is the go-to source for installing generally useful tools for developers. Homebrew's Python formula instructions explicitly state that these are the kinds of applications well-suited for packaging with Homebrew.
As dmgbuild is currently only compatible with Python 2.7 (OS X's system Python version), this also neatly side-steps the requirement to use Python 2.7 if using dmgbuild in a Python project. This is already possible with tools like pipsi, but again, those are focused on existing Python developers.
To create the dmgbuild formula, I used homebrew-pypi-poet to manage dependencies and automatically write resource stanzas for the formula.