Logging namespace

class LoggingDict(dict):
    def __setitem__(self, key, value):
        print("d[%r] = %r" % (key, value))
        dict.__setitem__(self, key, value)


class Meta(type):
    @classmethod
    def __prepare__(mcs, name, bases):
        return LoggingDict()


class C(metaclass=Meta):
    foo = 2+2
    foo = 42
    bar = 123

    def __int__(self):
        pass