copysort patch, was RE: [Python-Dev] inline sort option

Mark Russell marktrussell at
Mon Oct 20 18:04:12 EDT 2003

On Mon, 2003-10-20 at 22:43, Raymond Hettinger wrote:
> Let's see what the use cases look like under the various proposals:
>   [1] todo = [t for t in tasks.copysort() if due_today(t)]
>   [2] todo = [t for t in list.sorted(tasks) if due_today(t)]
>   [3] todo = [t for t in list(tasks, sorted=True) if due_today(t)]

Well, #3 is (I hope) a non-starter, given the need for the extra sort
keyword arguments.  And the instance method is less capable - it can't
sort a non-list iterable (except via list(xxx).copysort()).  So I would
definitely prefer #2, especially as I would tend to put:

	sort = list.sorted

at the top of my modules where needed.  Then I'd have:

	todo = [t for t in sort(tasks) if due_today(t)]
        genhistory(date, sort(events, key=incidenttime))
        for f in sort(os.listdir()): . . .

which to me looks enough like pseudocode that I'm happy.  This might
seem like an argument for having sort() as a builtin, but I think it's
still better as a list constructor. Adding "sort = list.sorted" to the
modules that need it is a small price to pay in boilerplate for the big
win of not cluttering the builtin namespace.

Mark Russell

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