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From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Tue, 30 Oct 2012 16:02:06 -0600
Subject: Re: Negative array indicies and slice()
To: Python <python-list@python.org>
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On Tue, Oct 30, 2012 at 3:55 PM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
> On Tue, Oct 30, 2012 at 8:21 AM, Andrew Robinson
> <andrew3@r3dsolutions.com> wrote:
>> D'Apriano mentioned the named values, start, stop, step in a slice() which
>> are an API and legacy issue;  These three names must also be stored in the
>> interpreter someplace.  Since slice is defined at the "C" level as a struct,
>> have you already found these names in the source code (hard-coded), or are
>> they part of a .py file associated with the interface to the "C" code?
>
> You mean the mapping of Python attribute names to C struct members?
> That's in sliceobject.c:
>
> static PyMemberDef slice_members[] = {
>     {"start", T_OBJECT, offsetof(PySliceObject, start), READONLY},
>     {"stop", T_OBJECT, offsetof(PySliceObject, stop), READONLY},
>     {"step", T_OBJECT, offsetof(PySliceObject, step), READONLY},
>     {0}
> };

Note that the slice API also includes the slice.indices method.

They also implement rich comparisons, but this appears to be done by
copying the data to tuples and comparing the tuples, which is actually
a bit ironic considering this discussion. :-)