[Python-Dev] Re: PEP 218 (sets); moving set.py to Lib

[François Pinard]

[Guido van Rossum]

I felt comfortable, or at least I think so, with all the contents of the
message.  All described compromises, not repeated here, seemed reasonable
to me.  Except maybe for the following:

> - The set constructors have an optional second argument, sort_repr,
>   defaulting to False, which decides whether the elements are sorted
>   when str() or repr() is taken.  I'm not sure if there would be
>   negative consequences of removing this argument and always sorting
>   the string representation.

Unless there is something deep attached to the properties of the sets
themselves, I do not understand why the sorting/non-sorting virtues of
`repr' should be tied with the constructor.

There is a precedent with dicts.  They print non-sorted, but they
pretty-print (through the `pprint' module) sorted.  Maybe the same could
be done for sets: use `pprint' if you want a sorted representation.
But otherwise, sets as well as dicts should print using the same order
by which elements are to be iterated upon or listed, in various other
circumstances.

-- 
François Pinard   http://www.iro.umontreal.ca/~pinard