Overriding a global

[Steven D'Aprano]

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.

-- 
Steven