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Groups > comp.lang.python > #101566

Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict

From Peter Otten <__peter__@web.de>
Newsgroups comp.lang.python
Subject Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict
Date 2016-01-12 19:09 +0100
Organization None
Message-ID <mailman.80.1452622185.13488.python-list@python.org> (permalink)
References <f2711b57-7b11-4fd5-8bab-a3e8581177b5@googlegroups.com> <n73c6f$uec$1@ger.gmane.org> <CALwzid=wLxZF0Qd0ZOCQRxmhmx60XEGZjWTez+UzyLbR7_Arhg@mail.gmail.com>

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Ian Kelly wrote:

> On Tue, Jan 12, 2016 at 10:12 AM, Terry Reedy <tjreedy@udel.edu> wrote:
>> Using the values views at intended (as an iterable):
>>
>>>>> dv = d.values()
>>>>> next(iter(dv))
>> 1
> 
> Good coding practice also dictates that whenever next is called, the
> potential StopIteration exception must be caught unless it is clearly
> intended to be propagated up to some generator. 

Even then you should be prepared for

https://docs.python.org/dev/whatsnew/3.5.html#pep-479-change-stopiteration-handling-inside-generators

> So more fully, this
> should be something like:
> 
> dv = iter(d.values())
> try:
>     next(dv)
> except StopIteration:
>     raise IndexError("d is empty")
> 
> At which point it may be desirable to extract that into a utility
> function.

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Thread

subscripting Python 3 dicts/getting the only value in a Python 3 dict Nick Mellor <thebalancepro@gmail.com> - 2016-01-12 08:50 -0800
  RE: subscripting Python 3 dicts/getting the only value in a Python 3 dict Emanuel Barry <vgr255@live.ca> - 2016-01-12 12:00 -0500
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Chris Angelico <rosuav@gmail.com> - 2016-01-13 04:06 +1100
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Terry Reedy <tjreedy@udel.edu> - 2016-01-12 12:12 -0500
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Bernardo Sulzbach <mafagafogigante@gmail.com> - 2016-01-12 15:18 -0200
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Peter Otten <__peter__@web.de> - 2016-01-12 18:32 +0100
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Ian Kelly <ian.g.kelly@gmail.com> - 2016-01-12 10:39 -0700
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-01-12 19:47 +0200
    Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Marko Rauhamaa <marko@pacujo.net> - 2016-01-12 21:42 +0200
      Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-01-12 22:18 +0200
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Peter Otten <__peter__@web.de> - 2016-01-12 19:09 +0100
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Bernardo Sulzbach <mafagafogigante@gmail.com> - 2016-01-12 16:48 -0200
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Peter Otten <__peter__@web.de> - 2016-01-12 19:59 +0100
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Bernardo Sulzbach <mafagafogigante@gmail.com> - 2016-01-12 17:12 -0200
    Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Steven D'Aprano <steve@pearwood.info> - 2016-01-13 12:29 +1100
      Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Bernardo Sulzbach <mafagafogigante@gmail.com> - 2016-01-13 13:53 -0200
  Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Steven D'Aprano <steve@pearwood.info> - 2016-01-13 12:23 +1100
    Re: subscripting Python 3 dicts/getting the only value in a Python 3 dict Grant Edwards <invalid@invalid.invalid> - 2016-01-13 15:58 +0000

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