Is there a way to get the sample weights that were used to fit a scikit-learn estimator?
A quick search of the source code, e.g. RandomForestClassifier's, doesn't find anywhere that sample_weight gets saved as a class attribute. I suspect that was a conscious decision: the sample weights are directly tied to the dataset, which also doesn't get saved for later use; that's why sample_weight appears in the fit method rather than the class instantiation.