patch in Python?

[Gerhard Häring]

Using the difflib module, I can create diffs between text files. Now,
has anybody written a patch-replacement in Python, yet?

The reason I'm asking is that I'm wrapping a library [1] whose license
requires that the sources are distributed unchanged. I don't need to
patch the library, yet, but in case I'll ever need, I'd need a Python
module to do the patching.

-- Gerhard

[1] http://www.tc.umn.edu/~ringx004/mapm-main.html