Python introspection and namespace weird question

[Chris Rebert]

On Mon, Dec 1, 2008 at 6:04 AM, Rayene Ben Rayana
<rayene.benrayana at gmail.com> wrote:
> Hello everybody,
>
> Is there an easy way to do something like this in python ?
>
>>>> red_car = MyVehicleClass()
>>>> car = red_car
>>>> car.labels()
> ['red_car' , 'car' ]
>
> In other words, does an instance has access to its name pointers ?

In short, No. (Cue another debate over whether Python uses call-by-X
semantics...)

Typically people who want to do such things actually want/should use a
dictionary mapping string keys to instance values instead.

Note that in certain limited cases, voodoo involving the locals() or
globals() built-in functions or the `inspect` module can work, but not
in the common general case. But generally these techniques are
considered bad style and kludgey unless you're writing a debugger or
something equally meta, with using a dictionary as explained
previously being much preferred.

For example, for your particular code above, the following happens to work:
[name for name, obj in locals().iteritems() if obj is car] #==>
['red_car' , 'car' ]

But this will only give the names in the current function of the
particular car object. Likewise, globals() works only for module-level
names, and the `inspect` module's magic only works for names in
calling functions (i.e. those below the current one in the callstack).

Cheers,
Chris
-- 
Follow the path of the Iguana...
http://rebertia.com

>
> Thanks in advance,
>
> Rayene
>
>
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