Type error Unhashable type:set

The individual items that you put into a set can’t be mutable, because if they changed, the effective hash would change and thus the ability to check for inclusion would break down.

Instead, you need to put immutable objects into a set – e.g. frozensets.

If you change the return statement from your enum method to…

return [frozenset(i) for i in L]

…then it should work.