Re: variable scope of class objects

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From	Luca Menegotto <otlucaDELETE@DELETEyahoo.it>
Newsgroups	comp.lang.python
Subject	Re: variable scope of class objects
Date	Thu, 22 Oct 2015 11:59:56 +0200
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Maybe I've been too cryptic. I apologize.

Il 22/10/2015 01:35, JonRob ha scritto:
> @Dennis,
>
>
> Thanks for your example.  My structure is very similar.

And that's ok. But you can also 'attach' the constants to a class, if it 
makes sense. For example, the same code of Dennis can be written as:

class SensorA():
     GYROXREG = 0x0010
     GYROYREG = 0x0011
     GYROZREG = 0x0001
     _registers = [GYROXREG, GYROYREG, GYROZREG]

And then you can invoke those constants as:

SensorA.GYROXREG

to emphasize that they are significant to this class, and to this class 
only.

>      Luca wrote...
>> Please, note that declaring a variable in the constructor is only a
>> convention: in Python you can add a variable to an object of a class
>> wherever you want in your code (even if it is very dangerous and
>> discouraged).

This is the cryptic part.
I mean: you can do, and it's perfectly legal:

class A():
     def __init__(self):
         self.a = 10

if __name__ == '__main__':
     o = A()
     print(o.a)
     # this is a new member, added on the fly
     o.b = 20
     print(o.b)

but, for God's sake, use it only if you have a gun at your head!

-- 
Ciao!
Luca

Thread

variable scope of class objects JonRob - 2015-10-19 14:39 -0400
  Re: variable scope of class objects Random832 <random832@fastmail.com> - 2015-10-19 15:01 -0400
    Re: variable scope of class objects JonRob - 2015-10-20 17:11 -0400
  Re: variable scope of class objects sohcahtoa82@gmail.com - 2015-10-19 16:19 -0700
    Re: variable scope of class objects Terry Reedy <tjreedy@udel.edu> - 2015-10-19 20:03 -0400
  Re: variable scope of class objects Nagy László Zsolt <gandalf@shopzeus.com> - 2015-10-20 07:31 +0200
  Re: variable scope of class objects Luca Menegotto <otlucaDELETE@DELETEyahoo.it> - 2015-10-20 08:17 +0200
    Re: variable scope of class objects Nagy László Zsolt <gandalf@shopzeus.com> - 2015-10-20 08:38 +0200
      Re: variable scope of class objects Luca Menegotto <otlucaDELETE@DELETEyahoo.it> - 2015-10-20 09:23 +0200
    Re: variable scope of class objects JonRob - 2015-10-20 17:33 -0400
      Re: variable scope of class objects Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-10-20 20:18 -0400
        Re: variable scope of class objects JonRob - 2015-10-21 19:35 -0400
          Re: variable scope of class objects Luca Menegotto <otlucaDELETE@DELETEyahoo.it> - 2015-10-22 11:59 +0200
      What does it mean for Python to have “constants”? (was: variable scope of class objects) Ben Finney <ben+python@benfinney.id.au> - 2015-10-21 11:27 +1100
      Re: What does it mean for Python to have “constants”? Nagy László Zsolt <gandalf@shopzeus.com> - 2015-10-21 08:13 +0200
      Re: variable scope of class objects Luca Menegotto <otlucaDELETE@DELETEyahoo.it> - 2015-10-22 07:55 +0200
      Re: variable scope of class objects Erik <python@lucidity.plus.com> - 2015-10-20 23:17 +0100

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