[Python-Dev] PEP for adding an sq_index slot so that any object, a or b, can be used in X[a:b] notation

[Jim Jewett]

Travis wrote:

>  The patch adds a new API function int PyObject_AsIndex(obj)

How did you decide between int and long?

Why not ssize_t?

Also, if index is being added as a builtin, should the failure
result be changed?  I'm thinking that this may become a
replacement for isinstance(val, (int, long)).  If so, it might
be nice not to raise errors, or at least to raise a more
specific subclass.  (Catching a TypeError and then
checking the message string ... does not seem clean.)

-jJ