zzzeek/sqlalchemy — pull request #93 by Callek (2014-05-29 17:47:41+00:00)
Title: once kwarg in event funcs is new in 0.9.4

event.listen and event.listen_for have a kwarg once added in 0.9.4 (not 0.9.3) CHANGELOG agrees with this as well. (as does my manual testing)