[Python-Dev] Indexing builtin sequences with objects which supply __int__

[Todd Miller]

Guido van Rossum wrote:

>>There has been some recent interest in the Numeric/numarray community 
>>for using array objects as indices
>>for builtin sequences.  I know this has come up before, but to make 
>>myself clear, the basic idea is to make the
>>following work:
>>
>>class C:
>>    def __int__(self):
>>          return 5
>>
>>object = C()
>>
>>l = "Another feature..."
>>
>>print l[object]
>>"h"
>>
>>Are there any plans (or interest) for developing Python in this direction?
>>
>
>I'm concerned that this will also make floats acceptable as indices
>(since they have an __int__ method) and this would cause atrocities
>like
>
>print "hello"[3.5]
>
>to work.
>
>--Guido van Rossum (home page: http://www.python.org/~guido/)
>
>
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That makes sense.    What if we specifically excluded Float objects from 
the conversion?   Are there any types that need to be excluded?    If 
there's a chance of getting a patch for this accepted,  STSCI is willing 
to do the work.

Todd

-- 
Todd Miller 			jmiller@stsci.edu
STSCI / SSG			(410) 338 4576