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Re:intersection, union, difference, symmetric difference for dictionaries

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From Dave Angel <davea@davea.name>
Subject Re:intersection, union, difference, symmetric difference for dictionaries
Date Tue, 25 Feb 2014 16:35:50 -0500 (EST)
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Show key headers only | View raw

 mauro <mauro@gmail.com> Wrote in message:
>  Dictionaries and sets share a few properties:
> - Dictionaries keys are unique as well as sets items
> - Dictionaries and sets are both unordered
> - Dictionaries and sets are both accessed by key
> - Dictionaries and sets are both mutables
> 
> So I wonder why operations such us intersection, union, difference, 
> symmetric difference that are available for sets and are not available 
> for dictionaries without going via key dictviews. 
> 

I certainly wouldn't be able to guess what they should be defined
 to do, since there are several equally obnoxious possibilities.
 

For instance,  take union for example.  What should be the result
 when you union two dicts that have the same key but different
 values for that key?


-- 
DaveA

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intersection, union, difference, symmetric difference for dictionaries mauro <mauro@gmail.com> - 2014-02-25 20:32 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries Nick Timkovich <prometheus235@gmail.com> - 2014-02-25 14:37 -0600
  Re: intersection, union, difference, symmetric difference for dictionaries Skip Montanaro <skip@pobox.com> - 2014-02-25 14:40 -0600
  Re: intersection, union, difference, symmetric difference for dictionaries Peter Otten <__peter__@web.de> - 2014-02-25 21:53 +0100
  Re: intersection, union, difference, symmetric difference for dictionaries Peter Otten <__peter__@web.de> - 2014-02-25 21:58 +0100
  Re: intersection, union, difference, symmetric difference for dictionaries Tim Chase <python.list@tim.thechases.com> - 2014-02-25 15:03 -0600
    Re: intersection, union, difference, symmetric difference for dictionaries Duncan Booth <duncan.booth@invalid.invalid> - 2014-02-25 22:21 +0000
      Re: intersection, union, difference, symmetric difference for dictionaries Tim Chase <tim@thechases.com> - 2014-02-25 16:35 -0600
      Re: intersection, union, difference, symmetric difference for dictionaries Tim Chase <python.list@tim.thechases.com> - 2014-02-25 16:36 -0600
      Re: intersection, union, difference, symmetric difference for dictionaries Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2014-02-25 22:58 +0000
    Re: intersection, union, difference, symmetric difference for dictionaries Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-02-25 23:10 +0000
      Re: intersection, union, difference, symmetric difference for dictionaries Tim Chase <python.list@tim.thechases.com> - 2014-02-25 20:21 -0600
  Re: intersection, union, difference, symmetric difference for dictionaries Ben Finney <ben+python@benfinney.id.au> - 2014-02-26 08:27 +1100
  Re:intersection, union, difference, symmetric difference for dictionaries Dave Angel <davea@davea.name> - 2014-02-25 16:35 -0500
  Re: intersection, union, difference, symmetric difference for dictionaries Peter Otten <__peter__@web.de> - 2014-02-25 22:54 +0100
  Re: intersection, union, difference, symmetric difference for dictionaries mauro <mauro@gmail.com> - 2014-02-25 22:02 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries mauro <mauro@gmail.com> - 2014-02-25 22:03 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries Tim Chase <python.list@tim.thechases.com> - 2014-02-25 16:10 -0600
  Re: intersection, union, difference, symmetric difference for dictionaries mauro <mauro@gmail.com> - 2014-02-25 22:11 +0000
    Re: intersection, union, difference, symmetric difference for dictionaries Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-02-25 22:35 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries MRAB <python@mrabarnett.plus.com> - 2014-02-25 23:07 +0000
    Re: intersection, union, difference, symmetric difference for dictionaries Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-02-26 00:37 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries Ben Finney <ben+python@benfinney.id.au> - 2014-02-26 10:14 +1100
  Re: intersection, union, difference, symmetric difference for dictionaries MRAB <python@mrabarnett.plus.com> - 2014-02-25 23:25 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries Grant Edwards <invalid@invalid.invalid> - 2014-02-25 20:44 +0000
  Re: intersection, union, difference, symmetric difference for dictionaries John Gordon <gordon@panix.com> - 2014-02-25 20:44 +0000
    Re: intersection, union, difference, symmetric difference for dictionaries Chris Angelico <rosuav@gmail.com> - 2014-03-02 09:29 +1100

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