Yapps (Yet Another Python Parser System) is an easy to use parser generator that is written in Python and generates Python code. There are several parser generator systems already available for Python, including PyLR, kjParsing, PyBison, and mcf.pars, but I had different goals for my parser. Yapps is simple, is easy to use, and produces human-readable parsers. It is not fast, powerful, or particularly flexible. Yapps is designed to be used when regular expressions are not enough and other parser systems are too much: situations where you may write your own recursive descent parser.