[Python-ideas] Universal set

[Marco Sulla]

assert(The set that contains everything is God)

Compile with -OO


On Mon, 10 Aug 2020 at 13:23, haael <haael at interia.pl> wrote:
>
>
> Forgive me if this has already been discussed.
>
>
> Could we add the idea of "negative" sets to Python? That means sets that
> contain EVERYTHING EXCEPT certain elements.
>
>
> First, let's have a universal set that contains everything.
>
>      assert element in set.UNIVERSAL
>
> The universal set is a superset of every other set.
>
>      assert set.UNIVERSAL >= any_set
>
> Adding anything to universal set doesn't change anything.
>
>      assert set.UNIVERSAL | element == set.UNIVERSAL
>
> However REMOVING an element from the set puts it on "negative list".
>
>      myset = set.UNIVERSAL
>      myset.remove(element)
>      assert element not in myset
>
> Intersection of a "negative set" with a normal set gives again a normal
> set. Union of two negative sets, or a negative set with a normal set,
> gives a negative set.
>
> The main issue: negative sets would not be iterable, but you can
> intersect them with the desired subdomain and iterate over.
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