sklearn.LabelEncoder with never seen before values

Question

If a sklearn.LabelEncoder has been fitted on a training set, it might break if it encounters new values when used on a test set.

The only solution I c

Answer 1

If it is just about training and testing a model, why not just labelencode on entire dataset. And then use the generated classes from the encoder object.

encoder = LabelEncoder()
encoder.fit_transform(df["label"])
train_y = encoder.transform(train_y)
test_y = encoder.transform(test_y)