scikit-learn/scikit-learn — pull request #460 by larsmans (2011-12-12 15:43:36+00:00)
Title: make BaseEstimator an abstract base class

Now that we have Python 2.6 as a requirement, we can use abstract base classes to prevent users from instantiating what they shouldn't instantiate. I've already used this in the Naive Bayes module.

Here's a patch that does the same trick for `BaseEstimator`. I'm putting this up as a PR because I wasn't sure if this is the direction that we want to take.