[Python-ideas] [Python-Dev] hello, new dict addition for new eve ?

Nathan Rice nathan.alexander.rice at gmail.com
Tue Jan 3 22:25:44 CET 2012

On Tue, Jan 3, 2012 at 4:02 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> On 1/3/2012 11:59 AM, Nathan Rice wrote:
>> This is slightly tangential, but I've always wondered... Why aren't
>> set operations implemented on dicts?  It is fairly natural to view a
>> dictionary as a set of (key, value) pairs.  Things like
>> subset/superset checking (with concomitant operator support) make
>> sense.  I have written stuff like set(dict1.items())<
>> set(dict2.items()) many times.
> As a said earlier in this thread, being able to view dicts as sets is such a
> good idea that it was already added a few years ago.
>>>> {1:1}.items() < {1:1, 2:2}.items()
> True

Yes, my apologies, I knew about views but I missed the part where they
have set operations.  I was under the impression when I wrote that
they were just plain iterators.  I try to keep current on Py3 nuances,
but since my work ties me to Py2, I will miss subtle but important
points like that from time to time.  I still don't think there is
anything wrong with having the comparison operations present on the
dictionary directly, it seems intuitive *to me*.  Of course I
understand that I may be an outlier in this (and it certainly wouldn't
be the first time :P).


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