def _sampling_strategy_auto(y, sampling_type):
    """Returns sampling target auto for over-sampling and not-minority for
    under-sampling."""
    if sampling_type == "over-sampling":
        return _sampling_strategy_not_majority(y, sampling_type)
    elif sampling_type == "under-sampling" or sampling_type == "clean-sampling":
        return _sampling_strategy_not_minority(y, sampling_type)
Returns sampling target auto for over-sampling and not-minority for
    under-sampling.
imblearn/utils/_validation.py