Yet another way to do mixins in Python

mixin.py

import inspect

def mixin(cls, *funcs):
    """
    Mix the specified class into the current class. If function names (as
    strings) are passed, then only those functions are mixed in.

    mixin() MUST be called within a class definition.

    Example:

        class Mixin1(object):
            def foo(self):
                pass
            def bar(self):
                pass
            def baz(self)
                pass

        class X(object):
            mixin(Mixin1) # gets all the methods

        class Y(object):
            mixin(Mixin1, 'foo') # only gets foo

        class Z(object):
            mixin(Mixin1, 'foo', 'baz') # gets foo and baz, but not bar

    Adapted from:

    http://code.activestate.com/recipes/498124-real-mixins/
    """
    locals = inspect.stack()[1][0].f_locals
    if "__module__" not in locals:
        raise TypeError("mixin() must be invoked within a class definition")

    # Copy the class's dict.
    dict = cls.__dict__.copy()

    # The true ugliness.
    slots = dict.pop("__slots__", [])

    if slots and "__slots__" not in locals:
        locals["__slots__"] = ["__dict__"]
    else:
        locals["__slots__"] = []

    names = set(funcs) if len(funcs) > 0 else set()
    new_dict = {}
    for name in dict:
        if not name.startswith("__"):
            if len(names) == 0 or name in names:
                locals["__slots__"].append(name)
                new_dict[name] = dict[name]

    # Mix the namespaces together.
    locals.update(new_dict)