On Wed, Jun 19, 2013 at 11:18 AM, <[email protected]> wrote:
> The second argument takes the tuple which determines which varialble(key) to
> use the comparator on. And the third determines whether to return the list in
> ascending or descending order.
That's not exactly correct. The arguments are listed in that order,
but in fact the arguments to list.sort are keyword-only and cannot be
supplied positionally. So the "args" argument is expected to be an
empty tuple, and the "kwds" argument is a dict that contains both the
"key" and "reverse" arguments, if they were supplied.
> But how do these PyObject* look in C?
It's a pointer to a struct that contains information like the class
and reference count of the object.
> How does a PyListObject* look declared in CPython.
That's a pointer to a larger struct that shares the same header as the
PyObject* struct (which is basically how you do inheritance in C). It
adds information like the length and capacity of the list, plus a
pointer to an array of PyObject* that stores the contents of the list.
> How would something like this list = [2, 1, 5, 6, 10] look in CPython. Or
> what about something more complicated -- mlist = [('A',1),('B',2),('C',3)].
To answer that question, you should really delve into the source and
see what these structs actually look like. But the first is going to
contain an array of five PyObject* values, each of which references an
int, while the second is going to contain an array of three PyObject*
values, each of which references a tuple.
I also recommend that you read the sections of the Python docs that
cover the C API, as those should help you understand how these structs
are normally handled.
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