I have a Scikit Learn ColumnTransformer containing a number of other transformers (passthrough, a custom transformer and a OneHotEncoder) that has been “trained” (transformer.fit() has been run on data) and stored in a Pickle file, created with Scikit Learn 1.1.2.

The OneHotEncoder seems to be the biggest challenge as the passthrough and the custom transformer should be compatible between the versions.

I need to find a way to convert this transformer from the old Scikit Learn version (1.1.2) to the newest version (1.5.1). How can this be done while maintaining all information stored in the transformers (what they have “learned”)?