Why accept kwargs but not use them?

Question

I was looking at the Django source code today and I noticed this:

class DjangoTestSuiteRunner(object):
    def __init__(self, verbosity=1, interactive=True, failfast=True, **kwargs):
        self.verbosity = verbosity
        self.interactive = interactive
        self.failfast = failfast

Why would they accept kwargs in the constructor but then not do anything with them?

Answer 1

This pattern can make backwards/forwards compatibility easier. If the newer/older version of the code has more/less parameters then you won't break everything.

Also, when you are inheriting this class (for example with mixins) it can be convenient to just accept everything.

Imho it's not a pretty pattern to use, but it works.