[BioPython] parser code

[Tim]

Hi,
When I was learning Bioperl, I used a book, Beginning Perl for
Bioinformatics. It gave a lot of information on how to write your own
parsers etc. Is there anything similar for python at the minute? It is
great that biopython has lots of parsers available, but it would be
great to see the code for these, with some explanations. Does this info
exists?

All the best,
Tim