.. blogpost::
    :title: scikit-learn internal API
    :keywords: API
    :date: 2020-09-02
    :categories: scikit-learn
    :lid: blog-internal-api-impurity-improvement

    The signature of method `impurity_improvement
    <https://github.com/scikit-learn/scikit-learn/blob/master/
    sklearn/tree/_criterion.pxd#L65>`_ will change for version
    0.24. That's usually easy to handle two versions of scikit-learn
    even overloaded in a class except that method is implemented
    in :epkg:`cython`. The method must be overloaded the same way
    with the same signature. The way it was handled is implemented
    in PR `88 <https://github.com/sdpython/mlinsights/pull/88>`_.

    The best would be to include both of them but only one of
    them can compile. I did not find any good solution to that.
    It compiles whatever scikit-learn's version but the compiled
    module only works with the installed version of
    :epkg:`scikti-learn`.