attrs is an MIT-licensed Python package with class decorators
that ease the chores of implementing the most common attribute-related
object protocols:

>>> import attr
>>> @attr.s
... class C(object):
...     x = attr.ib(default=42)
...     y = attr.ib(default=attr.Factory(list))
>>> i = C(x=1, y=2)

(If you don't like the playful attr.s and attr.ib, you can also use their
no-nonsense aliases attr.attributes and attr.attr).

You just specify the attributes to work with and attrs gives you:

    a nice human-readable __repr__,
    a complete set of comparison methods,
    an initializer,
    and much more

without writing dull boilerplate code again and again.

WWW: https://github.com/hynek/attrs