[Python-ideas] Extremely weird itertools.permutations

[David Mertz]

On Sat, Oct 12, 2013 at 8:07 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:

> One interesting point is that combining collections.Counter.elements()
> with itertools.permutations() currently does the wrong thing, since
> itertools.permutations() *always* considers iterable order significant,
> while for collections.Counter.elements() it's explicitly arbitrary.
>
I hadn't thought about it, but as I read the docs for 3.4 (and it's the
same back through 2.7), not only would both of these be permissible in a
Python implementation:

  >>> list(collections.Counter({'a':2,'b':1}).elements())
  ['a', 'a', 'b']

Or:

  >>> list(collections.Counter({'a':2,'b':1}).elements())
  ['b', 'a', 'a']

But even this would be per documentation (although really unlikely as an
implementation):

  >>> list(collections.Counter({'a':2,'b':1}).elements())
  ['a', 'b', 'a']

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