4 ms·

I agree, same with frozenset. If you really want to use one of those as a key, convert to a tuple. There might be niche use cases for all this, but it's not som

• boothby 11mo ago
  Problem being that sets aren't consistently ordered and conversion to a tuple can result in an exponential (specifically, factorial) explosion in the number of possible keys associated with a single set. Nor can you sort all objects. Safe conversion of sets to tuples for use as keys is possible but the only technique I know requires an auxiliary store of objects (mapping objects to the order in which they were first observed), which doesn't parallelize well.
  • morshu9001 11mo ago
    tuple(sorted(s)) and if you can't even sort the values, they're probably not hashable. I get that this involves a copy, but so does frozenset, and you can cross that bridge in various ways if it's ever a problem.
    • boothby 11mo ago
      Here are some types that support hashing: str bytes int, float complex tuple frozenset Aside from int and float, you cannot perform comparisons between objects of different types. Moreover, you cannot sort complex numbers at all. I have crossed that bridge, and I'm telling you (again) that a sorted tuple is not a generic solution.
      • morshu9001 11mo ago
        I'm not saying the problem with tuple doesn't exist, but that there doesn't need to be a built-in way to deal with it. If for some unfortunate reason you've got a mixed-type set that you also want to use as a dict key, you can write a helper.