Python "implements <interface>" equivalent?

[Wojciech Gryc]

Hi,

I recently started using Python and am extremely happy with how
productive it's made me, even as a new user. I'm hoping to continue
using the language for my research, and have come across a bit of a
stumbling block.

I'm a seasoned Java programmer and quite a big fan of interfaces...
i.e. The idea that if I make a number of distinct classes that
implement interface X, I can pass them all as parameters to functions
or whatnot that require an X object.

Is there something similar in Python?

What I'd like to do is create a feature detection system for my work
-- specifically, a general class / interface called "Feature" and then
subclasses that implement functions like isFeaturePresent() in all of
their different and unique ways. I'd love to hear how I can do this in
Python.

Thanks,
Wojciech