Hi folks,

Just a suggestion for a documentation tweak. Currently the docs for len() on a set say this:

   .. describe:: len(s)

      Return the cardinality of set *s*.

I'm a relatively seasoned programmer, but I don't really have a maths background, and I didn't know what "cardinality" meant. I could kind of grok it by context, but could we change this to something like the following?

   .. describe:: len(s)

      Return the number of elements in set *s* (cardinality of *s*).

Happy to open a bugs.python.org issue on this, but wanted to get general consensus first.