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Re: Toggle

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From Ian Kelly <ian.g.kelly@gmail.com>
Date Thu, 9 Oct 2014 10:07:28 -0600
Subject Re: Toggle
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On Wed, Oct 8, 2014 at 8:34 PM, Rustom Mody <rustompmody@gmail.com> wrote:
> On Thursday, October 9, 2014 7:12:41 AM UTC+5:30, Ben Finney wrote:
>> Seymore4Head writes:
>
>> > I want to toggle between color="Red" and color="Blue"
>
>> It's good to cultivate ongoing familiarity with the standard library
>
> And language. In recent python3:
>
>>>> class Color(Enum):
> ...   Red = 0
> ...   Blue = 1
> ...
>>>> Color.Red
> <Color.Red: 0>
>>>> print (Color.Red)
> Color.Red
>
> # Not sure what to make of that distinction...
>
>>>> c=Color.Red
>>>> c = Color.Blue if c==Color.Red else Color.Red
>>>> c
> <Color.Blue: 1>
>>>>
>
>>>> # Better
>>>> def toggle(c): return Color.Blue if c==Color.Red else Color.Red
> ...
>>>> toggle(c)
> <Color.Blue: 1>
>>>> toggle(c)
> <Color.Blue: 1>
>
> # which means the c has not changed

Python enums can have methods and properties, which means that toggle
could be implemented as such:

>>> class Color(Enum):
...   red = 0
...   blue = 1
...   def toggle(self):
...     return Color.blue if self is Color.red else Color.red
...
>>> Color.blue.toggle()
<Color.red: 0>
>>> Color.blue.toggle().toggle()
<Color.blue: 1>

(Note the recommended way to compare enum instances is with "is", not "==".)

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Thread

Toggle Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-10-08 20:11 -0400
  Re: Toggle Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-09 12:29 +1100
    [OT] spelling colour / color was Re: Toggle mm0fmf <none@mailinator.com> - 2014-10-09 18:43 +0100
      Re: [OT] spelling colour / color was Re: Toggle duncan smith <buzzard@invalid.invalid> - 2014-10-09 19:24 +0100
        Re: [OT] spelling colour / color was Re: Toggle Tim Delaney <timothy.c.delaney@gmail.com> - 2014-10-10 06:53 +1100
          Re: [OT] spelling colour / color was Re: Toggle Marko Rauhamaa <marko@pacujo.net> - 2014-10-09 23:48 +0300
            Re: [OT] spelling colour / color was Re: Toggle alister <alister.nospam.ware@ntlworld.com> - 2014-10-10 17:31 +0000
              Re: [OT] spelling colour / color was Re: Toggle Marko Rauhamaa <marko@pacujo.net> - 2014-10-10 22:01 +0300
                Re: [OT] spelling colour / color was Re: Toggle alister <alister.nospam.ware@ntlworld.com> - 2014-10-10 20:05 +0000
                Re: [OT] spelling colour / color was Re: Toggle Christian Gollwitzer <auriocus@gmx.de> - 2014-10-11 11:37 +0200
                Re: [OT] spelling colour / color was Re: Toggle mm0fmf <none@mailinator.com> - 2014-10-11 12:45 +0100
                Re: [OT] spelling colour / color was Re: Toggle duncan smith <buzzard@invalid.invalid> - 2014-10-11 16:26 +0100
                Re: [OT] spelling colour / color was Re: Toggle Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-10-11 15:20 -0400
                Re: [OT] spelling colour / color was Re: Toggle William Ray Wing <wrw@mac.com> - 2014-10-11 15:55 -0400
                Re: [OT] spelling colour / color was Re: Toggle duncan smith <buzzard@invalid.invalid> - 2014-10-12 00:40 +0100
                Re: [OT] spelling colour / color was Re: Toggle giacomo boffi <pecore@pascolo.net> - 2014-10-18 09:06 +0200
                Re: [OT] spelling colour / color was Re: Toggle Simon Ward <simon+python@bleah.co.uk> - 2014-10-11 15:45 +0100
        Re: [OT] spelling colour / color was Re: Toggle "Neil D. Cerutti" <neilc@norwich.edu> - 2014-10-10 10:46 -0400
        Re: [OT] spelling colour / color was Re: Toggle Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-10-10 18:45 +0100
      Re: [OT] spelling colour / color was Re: Toggle Terry Reedy <tjreedy@udel.edu> - 2014-10-09 18:53 -0400
        Re: [OT] spelling colour / color was Re: Toggle Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-10 18:11 +1100
          Re: [OT] spelling colour / color was Re: Toggle Marko Rauhamaa <marko@pacujo.net> - 2014-10-10 13:08 +0300
            Re: [OT] spelling colour / color was Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-10 21:40 +1100
              Re: [OT] spelling colour / color was Re: Toggle Marko Rauhamaa <marko@pacujo.net> - 2014-10-10 13:51 +0300
                Re: [OT] spelling colour / color was Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-10 22:50 +1100
                Re: [OT] spelling colour / color was Re: Toggle Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-10-10 20:19 -0400
                Re: [OT] spelling colour / color was Re: Toggle Marko Rauhamaa <marko@pacujo.net> - 2014-10-11 13:33 +0300
                Re: [OT] spelling colour / color was Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-11 22:03 +1100
      Re: [OT] spelling colour / color was Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-10 10:21 +1100
      Re: [OT] spelling colour / color was Re: Toggle Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-10 17:52 +1100
        Re: [OT] spelling colour / color was Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-10 18:04 +1100
      Re: [OT] spelling colour / color was Re: Toggle Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-10-10 18:38 +0100
  Re: Toggle Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-10-09 02:25 +0100
  Re:Toggle Dave Angel <davea@davea.name> - 2014-10-08 21:24 -0400
  Re: Toggle Ben Finney <ben+python@benfinney.id.au> - 2014-10-09 12:42 +1100
    Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-08 19:34 -0700
      Re: Toggle Steven D'Aprano <steve@pearwood.info> - 2014-10-09 04:56 +0000
        Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-08 22:39 -0700
          Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-09 16:55 +1100
          Re: Toggle Peter Otten <__peter__@web.de> - 2014-10-09 09:51 +0200
            Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-09 05:42 -0700
              Re: Toggle Terry Reedy <tjreedy@udel.edu> - 2014-10-09 16:57 -0400
          Re: Toggle Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-10 18:18 +1100
            Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-10 07:24 -0700
              Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-10 07:28 -0700
                Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-11 01:36 +1100
      Re: Toggle Ian Kelly <ian.g.kelly@gmail.com> - 2014-10-09 10:07 -0600
        Re: Toggle Rustom Mody <rustompmody@gmail.com> - 2014-10-09 09:33 -0700
          Re: Toggle Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-10 18:15 +1100
  Re: Toggle Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-10-09 04:02 +0100
  Re: Toggle random832@fastmail.us - 2014-10-08 23:54 -0400
  Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-09 14:57 +1100
  Re: Toggle Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-10-09 17:57 +1300
    Re: Toggle Travis Griggs <travisgriggs@gmail.com> - 2014-10-08 22:38 -0700
    Re: Toggle alister <alister.nospam.ware@ntlworld.com> - 2014-10-09 15:23 +0000
      Re: Toggle Tony the Tiger <tony@tiger.invalid> - 2014-10-12 18:38 +0000
        Re: Toggle Chris Angelico <rosuav@gmail.com> - 2014-10-13 05:43 +1100
          Re: Toggle alister <alister.nospam.ware@ntlworld.com> - 2014-10-13 08:09 +0000
  Re: Toggle Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2014-10-10 13:44 +0200

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