boisgera at isia.cma.fr
Thu Nov 25 19:13:21 CET 2004
Nick Coghlan <ncoghlan at email.com> wrote in message news:<41a5e084$0$25787$5a62ac22 at per-qv1-newsreader-01.iinet.net.au>...
> Peter Maas wrote:
> > What you are wondering about is the opposite direction
> > IF  works THEN __getitem__ in dict.
> > but this is not what the Python Reference Manual says. Im not a
> > Numeric expert but AFAIK Numeric arrays are basically C arrays
> > having  intrinsically so there's no need no deliver it via
> > __getitem__.
> This is correct, and true of any C extension - classes implemented in C only
> need to define the appropriate function pointers in their type structures in
> order for Python to find the relevant methods.
> Classes that are being *nice* about it put in the actual magic method names as
> well (e.g. try "list.__getitem__"), but it is by no means required.
Nick, Pierre, Peter,
Thanks for your answers. I guess that in the case of the Numeric
package, there was at least the *intent* to support __getitem__
because it is provided at the class level (which is not required,
>> from Numeric import *
>> a = array([3.14])
>> Array = type(a)
Traceback (most recent call last):
File "<stdin>", line 1, in ?
I guess that everything would work as expected if __class__ was defined at
the instance level ...
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