types.ClassType

We can provide a custom metaclass by setting __metaclass__ in a class definition to any callable that takes the same arguments as type.

When the Python interpreter executes a class statement […], it calls type with the following arguments:

• The name of the class as a string
• A tuple of base classes - for our example this is the ‘one-pl’ 1
• A dictionary containing members of the class (class attributes, methods, etc) mapped by their names