On 5/4/2012 8:00 AM, Peng Yu wrote:
On Fri, May 4, 2012 at 6:21 AM, Chris Angelico<ros...@gmail.com> wrote:
On Fri, May 4, 2012 at 8:14 PM, Peng Yu<pengyu...@gmail.com> wrote:
Thanks. This is what I'm looking for. I think that this should be
added to the python document as a manifestation (but nonnormalized) of
what "A set object is an unordered collection of distinct hashable
objects" means.
There are other things that can prove it to be unordered, too; the
exact pattern and order of additions and deletions can affect the
iteration order. The only thing you can be sure of is that you can't
be sure of it.
I agree. My point was just to suggest adding more explanations on the
details in the manual.
I am not sure how much clearer we can be in the language manual. The
word 'unordered' means just that. If one imposes an arbitrary linear
order on an unordered collection, it is arbitrary. It is frustrating
that people do not want to believe that, and even write tests depending
on today's arbitrary serialization order being deterministic
indefinitely. There is a section about this in the doctest doc, but
people do it anyway. I will think about a sentence to add.
--
Terry Jan Reedy
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