[Sqlalchemy-tickets] Issue #3093: MutableDict.setdefault doesn't return the new value (zzzeek/sqlalchemy)

[Thomas H. <iss...@bi...>]

New issue 3093: MutableDict.setdefault doesn't return the new value
https://bitbucket.org/zzzeek/sqlalchemy/issue/3093/mutabledictsetdefault-doesnt-return-the

Thomas Hervé:

MutableDict.setdefault was recently changed to properly propagate changes, but it broke the dictionary interface by not returning the value. You should be able to do that with a dict:

a = {}
a.setdefault('b', 1) += 1

But with the current MutableDict behavior, it will fail with a NoneError.