On Mon, Aug 20, 2007 at 03:14:24PM -0300, Ricardo Ar?oz wrote:
[snip]
> > You just work on a generated modified list.
> >
> > foo = range(1,6)
> > for i in [x*2 for x in foo]:
> > do_whatever_you_want_with(i)
> >
>
> What about :
>
> array = [1,2,3,4,5]
> array = [i * 2 for i in array]
>
Good solution.
However, consider the following:
>>> array = [1,2,3,4,5]
>>> array2 = array
>>> array = [i * 2 for i in array]
>>> array
[2, 4, 6, 8, 10]
>>> array2
[1, 2, 3, 4, 5]
So, did you want array2 to change, or not?
Your solution is a good one for situations where you do *not* want
array2 to change.
Here is a solution that changes the object that both array and
array2 refer to:
>>> array = [1, 2, 3, 4, 5]
>>> array2 = array
>>> for idx, item in enumerate(array):
array[idx] = item * 2
>>> array
[2, 4, 6, 8, 10]
>>> array2
[2, 4, 6, 8, 10]
Basically, this modifies the list "in place", rather than making a
new list from the old one.
Dave
--
Dave Kuhlman
http://www.rexx.com/~dkuhlman
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