[Numpy-discussion] argmax() return type can't index python lists

[Zachary Pincus]

Thanks for your reply, Travis.

> Note that the __index__ PEP I wrote was just accepted and checked- 
> in so in fact *all* numpy scalar types will be acceptable as  
> indices in Python2.5 (but we have to write the code for that still  
> in numpy).  So, it's possible that something in Python 2.5 changed  
> is causing it not to work.
>
> This very-well could be a bug in the new implementation of __index__.

The problem is that I can't reproduce this bug outside of numpy. If I  
go to the python people, they'll most likely say it's a numpy  
problem, unless I can show some other test case. Right now, all of  
the following classes work as indices in 2.5. The only thing that  
doesn't work is a raw numpy.int32 value.

I'd be happy to file a bug report on python if I could figure out a  
test case.

Zach

Cases which work fine:

class int_sublcass(int): pass

class empty(object): pass

class int_1(int, empty): pass

class int_2(empty, int): pass

class int_numpy_1(numpy.signedinteger, int):
   def __init__(self, i):
     int.__init__(self, i)

class int_numpy_2(int, numpy.signedinteger):
   def __init__(self, i):
     int.__init__(self, i)


l = [1,2,3]
l[int_sublcass(1)]
l[int_1(1)]
l[int_2(1)]
l[int_numpy_1(1)]
l[int_numpy_2(1)]