Here's a link with a good intro to the tools:
http://www.biocodershub.net/community/a-hitch-hikers-guide-to-biopython-sequences-and-alphabets/
- Reading and writing common sequence (and other) file formats
- Classes for the usual datatypes (sequences, alignments etc.)
- Functions for the usual things you’d do with those datatypes (alignments, Blasting)
- Facilities for data base queries
- A very large etc., etc. There’s a lot in there.