[Numpy-discussion] how to use the name of a ndarray as a string

Chris.Barker Chris.Barker@noaa....
Mon Nov 14 11:26:04 CST 2011


On 11/10/11 3:57 AM, Olivier Delalleau wrote:
> In such a situation you should probably use a dictionary from the start,

all good suggestions, but while we're at it:

On 11/10/11 2:17 AM, Chao YUE wrote:
> Does anyone know how I can quickly use the name of a ndarray as a string?

This reflects a key misunderstanding of how Python works -- a ndarray ( 
or any python object) does not "have a name".

when you write:

index=np.arange(100)

you are creating a ndarray object, and _binding_ the name "index" to it. 
the object exists apart from it's name:

l =[]

l.append(np.arange(100))

now there is a an andarray object in the list -- but it has no name. You 
can also bind multiple names to the same object:

index=np.arange(100)
fred = index
john = index

now "index", "fred", and "john" are all bound to the same object -- what 
would be its name now?

Hence Olivier's suggestionss -- al various ways to store and refere to 
objects -- binding to a variable is only one way.

This is a good read that should clarify it all:

http://python.net/~mwh/hacks/objectthink.html

-Chris



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Christopher Barker, Ph.D.
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