The patch for bsddb3 looks good, however there's no reason (IMHO) to keep in the tests those "if sys.version_info[0] < 3:" or replace the version with (2,6) since we are already using things like assertIn that are 2.7-only. I changed it only to avoid warnings, and left it unchanged in other places (not related to this issue) and in dbtables.py (to preserve compatibility in the unlikely case that someone wants to try running 2.7's bsddb with older versions of Python).
Attached a new patch.