I think you neglected the line in front of it, which does define FooBase. 1. >>> FooBase = type("FooBase", (object,), {}) 2. >>> Foo = type("Foo", (Foo

I think you neglected the line in front of it, which does define FooBase. 1. >>> FooBase = type("FooBase", (object,), {}) 2. >>> Foo = type("Foo", (FooBase,), {'bar' : 42}) Although I am not a python expert, so you may be right... in which case, how does line one not work?