Converting between two sets of constants

I have two enums NAME and ALIAS which are guaranteed to have the same number of constants, and I need a way to convert each constant from NAME to its corresponding one from ALIAS, and vice-versa. For example:

def name_to_alias(name):
    if name == Name.PAUL:
        return Alias.STARCHILD
    elif name == Name.GENE:
        return Alias.DEMON
    ...

def alias_to_name(alias):
    if alias == Alias.STARCHILD:
        return Name.PAUL
    elif alias == Alias.DEMON:
        return Name.GENE
    ...

I don't wish to maintain two functions (or dicts) like these. Ideally, I'd have the enum mappings in a single data structure which I can access from both conversion functions.

I'm thinking of something like:

mappings = {
    Name.PAUL: Alias.STARCHILD
    Name.GENE: Alias.DEMON
    ...
}

This would work for converting from Name to Alias, but the opposite may have issues (what happens if I make a copy-paste error and end up with two dict keys with the same value?). Is there an easy and safe way to achieve this?

Solution

Considering that could occur that in mappings more than one name could have the same alias a safe function should raise an error, like

mappings = {
    Name.PAUL: Alias.STARCHILD,
    Name.GENE: Alias.DEMON,
    Name.PETER: Alias.CATMAN,
    Name.ALICE: Alias.DEMON
}

def alias_to_name(alias):
#check if the alias is more than once in the mappings and raise an error
    if list(mappings.values()).count(alias) > 1:
        raise ValueError('Alias is not unique', alias, [name for name, a in mappings.items() if a == alias])
    else:
        return [name for name, a in mappings.items() if a == alias]

That will output

('Alias is not unique', <Alias.DEMON: 2>, [<Name.GENE: 2>, <Name.ALICE: 4>])