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Re: Overriding a global

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Date Tue, 13 Dec 2011 14:30:42 +0100
From Jean-Michel Pichavant <jeanmichel@sequans.com>
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To Steven D'Aprano <steve+comp.lang.python@pearwood.info>
Subject Re: Overriding a global
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Steven D'Aprano wrote:
> On Tue, 13 Dec 2011 10:54:51 +0100, Jean-Michel Pichavant wrote:
>
>   
>> Steven D'Aprano wrote:
>>     
>>> On Mon, 12 Dec 2011 12:13:33 +0100, Jean-Michel Pichavant wrote:
>>>
>>>
>>>       
>>>> Using the same name for 2 different objects is a bad idea in general.
>>>>     
>>>>     
>>>>         
>>> We have namespaces precisely so you don't need to care about making
>>> names globally unique.
>>>
>>>
>>>
>>>       
>> I don't get your point, namespaced names are unique, by definition.
>>
>> foo.aname <> bar.aname
>>     
>
> Assuming foo and bar are not names for the same object, there are at 
> least three namespaces here: the local namespace, where foo and bar can 
> be found, the foo.__dict__ namespace, and the bar.__dict__ namespace.
>
>
>   
>> The OP showed a code where there was a confusion between a global name
>> and a local one. There's no namespace involved. Having a local name
>> identical to a global one is a bad idea, def.
>>     
>
> Of course there are namespaces involved. There is the global namespace, 
> and the local namespace. That's how you can have x inside a function 
> without it overwriting global x outside of it, because they are different 
> namespaces. Which is my point.
>
> When I write this:
>
> x = 1
>
> def spam():
>     x = 2
>
> def ham():
>     x = 3
>
> The three x's don't clash because they are in three separate namespaces.
>
>   
I know that, why do I have the feel this is juste a semantic issue ?
Aren't you/I/we confusion namespaces & scopes ?

Anyway, semantic is not what we're interested in here.

writing

x = 1

def spam():
    x = 2


is in general a bad idea. That was my point.

JM

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Thread

Overriding a global Roy Smith <roy@panix.com> - 2011-12-10 15:47 -0500
  Re: Overriding a global MRAB <python@mrabarnett.plus.com> - 2011-12-10 21:07 +0000
    Re: Overriding a global Roy Smith <roy@panix.com> - 2011-12-10 16:10 -0500
      Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-12 12:13 +0100
        Re: Overriding a global Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-12-12 21:28 +0000
          Re: Overriding a global Dave Angel <d@davea.name> - 2011-12-12 16:43 -0500
            Re: Overriding a global Ben Finney <ben+python@benfinney.id.au> - 2011-12-13 09:27 +1100
              Re: Overriding a global Dave Angel <d@davea.name> - 2011-12-12 20:46 -0500
              Re: Overriding a global Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-12-13 01:48 +0000
              Re: Overriding a global Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-12 22:50 -0700
              Re: Overriding a global Joshua Landau <joshua.landau.ws@gmail.com> - 2011-12-13 08:34 +0000
              Re: Overriding a global Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-13 12:34 -0700
              Re: Overriding a global Ian Kelly <ian.g.kelly@gmail.com> - 2011-12-13 12:54 -0700
          Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-13 10:54 +0100
            Re: Overriding a global Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-12-13 11:15 +0000
              Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-13 14:30 +0100
              Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-14 11:14 +0100
              Re: Overriding a global Chris Angelico <rosuav@gmail.com> - 2011-12-14 21:32 +1100
              Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-14 13:05 +0100
                Re: Overriding a global Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-12-14 12:53 +0000
                Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-14 14:35 +0100
              Re: Overriding a global Chris Angelico <rosuav@gmail.com> - 2011-12-14 23:21 +1100
              Re: Overriding a global Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-12-14 18:06 +0100
  Re: Overriding a global Terry Reedy <tjreedy@udel.edu> - 2011-12-10 19:14 -0500
  Re: Overriding a global Terry Reedy <tjreedy@udel.edu> - 2011-12-10 19:19 -0500
  Re: Overriding a global Peter Otten <__peter__@web.de> - 2011-12-11 09:14 +0100
  Re: Overriding a global Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2011-12-13 10:15 +0100

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