That's not just simple operator overloading. What mitsuhiko refers to is that iter() can iterate over an object not just when you implement __iter__() but also

That's not just simple operator overloading. What mitsuhiko refers to is that iter() can iterate over an object not just when you implement __iter__() but also when you implement __getitem__() and __len__(), bool() has similar semantics as do several other functions and operators.