Sander Sweers a écrit :
On Sun, Nov 2, 2008 at 13:32, Kent Johnson <[EMAIL PROTECTED]> wrote:
Use a list comprehension:
somelist = [ x+1 for x in somelist ]
Got it.
Note that this creates a new list, replacing the one that was in
somelist. If you need to actually modify somelist in place (rare) then
use somelist[:] = [ x+1 for x in somelist ]
which creates a new list, then replaces the *contents* of somelist
with the contents of the new list.
In what (rare) situation would you use this?
[post sent again -- seems not to have reached the list -- ??]
When you need to cleanup or normalize the objects held in a list. For instance,
in text processing:
lines = text.splitlines()
lines = [line.strip() for line in lines]
or e.g.
lines = [line.lower() for line in lines]
Both "pre-processing" actions that will make further processing more
straitforward. Note that you can chain actions:
lines = [line.strip().lower() for line in lines]
Denis
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