You could create such a class with a few lines of code by inheriting from
collections.abc.MutableSet
You as anyone with a pontual problem that would benefit from such a
construct -
I can't see why/when this would be useful unless in a project already
dealing
with symbolic/lazy mathematical concepts - in which case, the author would
be already aware of these possibilities.
On Mon, 10 Aug 2020 at 08:23, haael
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. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/MY77JS... Code of Conduct: http://python.org/psf/codeofconduct/