The new “Biopython” logo with yellow and blue snakes forming a double helix was created by Patrick Kunzmann in 2017, and was first used in Biopython release 1.70.
This logo replaced the original logo, created by Henrik Vestergaard and Thomas Hamelryck in 2003. Inspired by the structure of DNA, it showed two golden pythons twisting in opposite directions to form a double helix around the word Biopython:
This design was chosen from panel of entries to an open competition on the mailing lists back in Summer 2003.
This picture shows the nine entries for the competition (taken from Brad Chapman’s BOSC 2003 talk):