Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #101563

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

Show all headers | View raw

Nick Mellor writes:

> Hi all,
>
> Seemingly simple problem:
>
> There is a case in my code where I know a dictionary has only one item
> in it. I want to get the value of that item, whatever the key is.
>
> In Python2 I'd write:
>
>>>> d = {"Wilf's Cafe": 1}
>>>> d.values()[0]
> 1
>
> and that'd be an end to it.
>
> In Python 3:

If you are happy to give the sole value a name:

   >>> shoe = dict(it=math.pi)
   >>> [o] = shoe.values()
   >>> o
   3.141592653589793

You might be able to use * to pass the sole value to a function:

   >>> print(*shoe.values())
   3.141592653589793

But the most readable thing might be to have a function that extracts
the sole value by whatever means:

   >>> def sole(d): [o] = d.values() ; return o
   ... 
   >>> sole(shoe)
   3.141592653589793

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

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

csiph-web