[Python-ideas] [Python-Dev] hello, new dict addition for new eve ? (original) (raw)

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).

Nathan

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