Hi.
The explanation on that page may be a bit confusing, so I will add to it.
If you think of L * n as something similiar to doing a shallow copy of
the list L n times, then it makes some sense:
>>> a = []
>>> L = [[]]
>>> for i in xrange(5):
... a.append(L[:][0])
has the same (or similiar) effect as
>>> a = [[]]*5
Both have the side effect noted in the text: that
>>> a[0].append(42)
modifies a single list, as you can see if you ask for a unique identifier:
>>> [id(e) for e in L]
[number repeated 5 times]
The alternative way:
>>> L = [[] for i in xrange(5)]
works because the code "[]", which creates a new empty list, is
executed 5 times, and creates 5 different lists.
On 8/2/07, Kent Johnson <[EMAIL PROTECTED]> wrote:
> Yang wrote:
> > So, can somebody tell me how the * operator of list and tuple work,
> > and how can we make use of it?
>
> A bit more here:
> http://docs.python.org/lib/typesseq.html
>
> See especially note (2)
>
> Kent
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