On Wed, Sep 24, 2008 at 2:02 PM, David Di Biase <da**********@gmail.comwrote:
Hi,
I have a rather large list structure with tuples contained in them (it's
part of a specification I received) looks like so:
[(x1,y1,r1,d1),(x2,y2,r2,d2)...]
The list can range from about 800-1500 tuples in size and I'm currently
sorting it with this:
a_list.sort(lambda a, b: cmp(b[3], a[3]))
You'd probably be better off using the 'key' keyword argument to
..sort(), which is made for the Schwartzian Transform:
a_list.sort(key=lambda x: x[3])
This sorts the list items by the value produced by the key function
for each item. It's also (IIRC) faster than using a comparison
function like you're currently doing.
Regards,
Chris
>
I'm actually sorting it by the last value in the tuple (d2). I have been
researching more efficient sorting algorithms and came across Schwartzian
transform via these links:
http://www.biais.org/blog/index.php/...ing-efficiency
http://dev.fyicenter.com/Interview-Q...n_Python_.html
I get what's happening (sorta...errr...lol) but I'm not sure if it is more
efficient in my scenario, if it is then I have no idea how to implement it
properly :-/
Would be great if a true expert would offer a suggestion for me...
Thanks!
David
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