Adam DePrince wrote:
> On Thu, 2006-03-30 at 23:37 -0800, Neal Norwitz wrote:
>> On 3/30/06, Terry Reedy <[EMAIL PROTECTED]> wrote:
>>> "Aahz" <[EMAIL PROTECTED]> wrote in message
>>> news:[EMAIL PROTECTED]
>>>> What do we want to tell people who have code like this:
>>>>
>>>> keys = d.keys()
>>>> keys.sort()
>>> Could a good-enough code analyzer detect such, even if separated by
>>> intervening lines? If so, it could suggest sorted() as a fix. I wonder if
>>> the pypy analyzer could be adapted for 2.x to 3.0 warning and upgrade
>>> purposes. Or do pylint or pychecker gather enough information?
>> pychecker is supposed to have this info, but only if d is known to be
>> a dict. It could be extended to assume any method keys() (and
>> friends) should return iterators. In which case, it would say that an
>> iterator doesn't have a sort method. Below is the output of the
>> current version.
>
> With the views that we were talking about before, with d.keys() all you
> have is the view, neither an iter nor list have been instantiated.
>
> I'd almost say that
>
> keys = d.keys()
> foo = keys.sort()
>
> could fit quite well into the view framework.
Not a good idea, since the long history of "list.sort()" encourages people to
think of the sort() method as an inplace operation, which it wouldn't be on a
view. "sorted()", on the other hand, already creates a new object. The only
downside is that Py2.x & Py3k compatible code would look like:
keys = sorted(d.keys())
which is likely to create the list *twice* in Py2.x.
Cheers,
Nick.
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---------------------------------------------------------------
http://www.boredomandlaziness.org
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