My initial understanding of this was flawed. Since we need to support the old string values we can't just have CUMTIME and CUMULATIVE map to "cumulative" because then "cumtime" is gone (unless we do extra work, which I see you did).

What we need here is a MultiValueEnum, so SortKey.CUMULATIVE maps to both "cumulative" and "cumtime".

The Enum should look like this:

class SortKey(str, Enum):

    CALLS = 'calls', 'ncalls'
    CUMULATIVE = 'cumulative', "cumtime"
    MODULE = 'module', 'filename', 'file'
    LINE = 'line'
    NAME = 'name'
    NFL = 'nfl'
    PCALLS = 'pcalls'
    STDNAME = 'stdname'
    TIME = 'time', 'tottime'

    def __new__(cls, *values):
        obj = object.__new__(cls)
        # first value is canonical value
        obj._value_ = values[0]
        for other_value in values[1:]:
            cls._value2member_map_[other_value] = obj
        obj._all_values = values
        return obj

Operations like SortKey('file') will return SortKey.MODULE. The downside is that SortKey.FILE is undefined, but I think that is an acceptable trade-off since we are still supporting the original string values, and those values can be used to get a correct SortKey member.