Hi @aniq63

Thanks a lot for your contribution.

We need to split this PR into 3, one per class.

We also need to update the documentation relevant for each transformer, which you'll find inside the docs folder. Basically, we need to replace all calls to the old transformer names by the new transformer names.

We also need to rename files from if necessary, for example if a file was called meanmedianimputer.py or .rst, we need to rename that to the new name of the transformer.

There is also this PR that adds the same changes #972, so maybe you could start with MissingIndicator, and we take it from there?

Note that the classes are tested in additional files and need to be updated there too: (tests/check_estimators_with_parametrize_tests.py, tests/test_imputation/test_check_estimator_imputers.py)

Closing this PR as requested since the changes have been split into separate PRs. Thank you for the feedback!

The new Seprate PR are following:

Rename MeanMedianImputer to MeanImputer #975

Rename AddMissingIndicator to MissingIndicator with deprecation support- #976
#976

Rename ArbitraryNumberImputer to ArbitraryImputer with deprecation support- #977
#977