scikit-learn/scikit-learn — pull request #3113 by hxu (2014-04-27 08:05:06+00:00)
Title: Fix LabelBinarizer and LabelEncoder fit and transform signatures to work with Pipeline

`fit`, `transform`, and `fit_transform` previously only accepted a single argument, which breaks when used within a Pipeline, since Pipeline always calls `fit_transform` with a second `y` argument, even if it is `None`.

See Issue #3112