You accumulate a lot of LaTeX projects when doing academic work. If you were smart, you used a citation manager starting from the beginning, slowly snowballing the citations you needed so you could just output a .bib file whenever you needed it for a new project. If you were smart.

Anyways, I had a bunch of .bib files from a bunch of projects that had a lot of overlapping citations. I couldn't find an easy-to-use tool that let me quickly move through them and merge .bib files without duplicates/conflicts that broke my LaTeX compilation. As such, I wrote a little Python script to quickly slam two .bib files together, using a Git merge as a template. The script lets you merge two files, or dedup bibtex entries in a single file.