At 07:15 PM 6/23/2008, Kent Johnson wrote:
On Mon, Jun 23, 2008 at 8:09 PM, Dick Moores <[EMAIL PROTECTED]> wrote:
> def sort_tuple_list_by_2nd_elements(alist):
> alist.sort
Doesn't do anything.
> alist_tup_elements_reversed = []
> for x in alist:
> alist_tup_elements_reversed.append((x[1], x[0]))
You should learn how to use list comprehensions:
alist_tup_elements_reversed.append = [ (x[1], x[0]) for x in alist ]
Now, that's why I don't use them. They don't make sense, I thought.
But that's a typo, or a paste-o, right? You meant
alist_tup_elements_reversed = [ (x[1], x[0]) for x in alist ], which works.
That's a start. Thanks
> alist_tup_elements_reversed.sort()
> print alist_tup_elements_reversed
>
> alist_tup_elements_reversed_and_reversed_again = []
> for x in alist_tup_elements_reversed:
> alist_tup_elements_reversed_and_reversed_again.append((x[1], x[0]))
Another list comp and you have pretty much reinvented
decorate-sort-undecorate (second time in a week for that!) - google it
or see my link in previous thread.
I plan to study your essay of sorting at
<http://personalpages.tds.net/~kent37/kk/00007.html>.
Also, one of the authors of OOPIP
(<http://www.prenhall.com/goldwasser/>), Michael Goldwasser (who
reads this list), wrote me directly, suggesting I skip ahead in his
book to chapter 14, "Sorting Algorithms", and read the first few
pages. Looks understandable to me, so I will, even though that's a
skip-ahead of about 300 pages for me.
Dick
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