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Re: I have no class

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On 11/23/2014 10:54 AM, Seymore4Head wrote:
> On Sun, 23 Nov 2014 10:16:28 -0500, Dave Angel <davea@davea.name>
> wrote:
>
>> On 11/23/2014 05:52 AM, Seymore4Head wrote:
>>> On Sun, 23 Nov 2014 17:00:08 +1100, Chris Angelico <rosuav@gmail.com>
>>> wrote:
>>>
>>>>
>>>> 1) Python's namespacing rules mean that 'key' is a part of the RPS
>>>> class, and can be referred to as 'self.key' or as 'RPS.key'
>>>> 2) Use of 'self.key' for the textual form of the throw is shadowing
>>>> the first of those reference names (but it's a poor name anyway)
>>>> 3) A list would work just as well as a dictionary here, since your
>>>> indices are sequential and start from zero
>>>> 4) There's another function in the random module which can do both of
>>>> your steps at once.
>>>>
>>>> Thank you for helping us help you help us all!
>>>>
>>>> ChrisA
>>>
>>> I wish I could explain my problems so precisely.  I will try to do
>>> better in the future.
>>> Thanks
>>>
>>> I will also try this using a list instead of a dictionary.
>>>
>>
>> And please avoid the shadowing.  It's confusing whenever the same name
>> is used for a class attribute and an instance attribute of the same
>> class.  it can be useful for defaults and such, but not here.
>>
>>   class RPS:
>>       KEY_TABLE={0:"rock", 1:"paper",2:"scissors"};
>>    or
>>       KEY_TABLE= ("rock", "paper", "scissors")
>>       def __init__(self):
>>           self.throw=random.randrange(3)
>>           self.key=RPS.KEY_TABLE[self.throw]
>>
>> Note I also capitalized the tuple name, which is a convention saying we
>> don't intend to modify it.
>
> I just learned by trial and error if I moved "key" out of the class, I
> could still use it in the class without having to give it a RPS
> extension.

It's not an extension, it's a namespace qualifier.  That's a good thing, 
to constrain a particular name to as narrow a scope as possible.  In 
other words, instead of making it a global variable, put it in the 
namespace that gives it meaning.

>
> I also changed it to a list and it works fine.
>
> Thanks
>
> key =["rock", "paper", "scissors"]
> class RPS:
>      def __init__(self):
>          self.throw=random.randrange(3)
>          self.key=key[self.throw]
>

But it belongs in the class, doesn't it?  If other code wants to use it, 
it'd be better if all references were of the form  RPS.KEY_TABLE.  And 
it should be a tuple, not a list, as you're not planning to change it.



-- 
DaveA

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Thread

I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 21:47 -0500
  Re: I have no class random832@fastmail.us - 2014-11-22 22:08 -0500
    Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 22:16 -0500
  Re: I have no class Rustom Mody <rustompmody@gmail.com> - 2014-11-22 19:09 -0800
    Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 22:18 -0500
  Re: I have no class Ned Batchelder <ned@nedbatchelder.com> - 2014-11-22 22:14 -0500
    Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 22:35 -0500
      Re: I have no class Joel Goldstick <joel.goldstick@gmail.com> - 2014-11-22 22:52 -0500
        Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 23:15 -0500
          Re: I have no class Chris Angelico <rosuav@gmail.com> - 2014-11-23 17:00 +1100
            Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-23 05:52 -0500
              Re: I have no class Dave Angel <davea@davea.name> - 2014-11-23 10:16 -0500
                Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-23 10:54 -0500
                Re: I have no class Dave Angel <davea@davea.name> - 2014-11-23 11:14 -0500
                Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-23 11:49 -0500
                Re: I have no class Chris Angelico <rosuav@gmail.com> - 2014-11-24 03:59 +1100
                Re: I have no class Rustom Mody <rustompmody@gmail.com> - 2014-11-23 09:02 -0800
                Re: I have no class Steven D'Aprano <steve@pearwood.info> - 2014-11-24 04:21 +0000
                Re: I have no class Dave Angel <davea@davea.name> - 2014-11-24 00:11 -0500
                Re: I have no class Chris Angelico <rosuav@gmail.com> - 2014-11-24 16:11 +1100
                Re: I have no class Dan Sommers <dan@tombstonezero.net> - 2014-11-24 13:44 +0000
                Re: I have no class Chris Angelico <rosuav@gmail.com> - 2014-11-25 00:48 +1100
                Re: I have no class Dave Angel <davea@davea.name> - 2014-11-24 00:20 -0500
                Re: I have no class Chris Angelico <rosuav@gmail.com> - 2014-11-24 16:21 +1100
                Re: I have no class Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2014-11-24 13:47 -0500
      Re: I have no class Rustom Mody <rustompmody@gmail.com> - 2014-11-22 19:55 -0800
        Re: I have no class Seymore4Head <Seymore4Head@Hotmail.invalid> - 2014-11-22 23:19 -0500
        Re: I have no class Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-23 15:35 +0000

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