metaclass-boilerplate ===================== Most Python files should include the following boilerplate at the top of the file, right after the comment header and ``from __future__ import``: .. code-block:: python __metaclass__ = type Python 2 has "new-style classes" and "old-style classes" whereas Python 3 only has new-style classes. Adding the ``__metaclass__ = type`` boilerplate makes every class defined in that file into a new-style class as well. .. code-block:: python from __future__ import absolute_import, division, print_function __metaclass__ = type class Foo: # This is a new-style class even on Python 2 because of the __metaclass__ pass