Here's a fork (by the original author's request) of Will McGugan's ChessPy module. This Python module cannot play chess but it does know the rules of chess, so it can verify that moves are valid, or accept notation as input and provide visual representations. I used it for my Dada Chess project.
This fork of the library has fewer bugs, a few unit tests, and includes knowledge about the HTML entities used to represent chess characters.
Download it now.