John Salerno wrote:
I'm having some slight trouble understanding exactly why this creates an
infinite loop:
L = [1, 2]
L.append(L)
I tried this with Python 2.3.5 and it handles this tailbiter in a
very pleasantly surprising way:
l = [ 0, 1 ]
l.append( l )
l
[0, 1, [...]]
l[2]
[0, 1,
I'm having some slight trouble understanding exactly why this creates an
infinite loop:
L = [1, 2]
L.append(L)
In a highly abstract way, I understand it. But if I were asked to write
down what I think L is after the second line executes, I would write:
[1, 2, [1, 2]]
But the correct answer
On 2/13/06, John Salerno [EMAIL PROTECTED] wrote:
I'm having some slight trouble understanding exactly why this creates an
infinite loop:
L = [1, 2]
L.append(L)
'L' is a pointer to a list. You are now adding that pointer to the
very list it points to.
What you're looking for is:
L = [1, 2]
Peter Decker wrote:
'L' is a pointer to a list. You are now adding that pointer to the
very list it points to.
I understand that, but I guess I just don't see how this creates
anything other than a list that refers to [1, 2], and then refers again
to [1, 2], to create [1, 2, [1, 2]].
John Salerno wrote:
L.append(L) basically creates this, I think:
[1, 2, L]
Now, assuming that's correct, and since L points to the list [1, 2]
L points to [1, 2, L]
/F
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On Mon, 2006-02-13 at 16:03, John Salerno wrote:
Peter Decker wrote:
'L' is a pointer to a list. You are now adding that pointer to the
very list it points to.
I understand that, but I guess I just don't see how this creates
anything other than a list that refers to [1, 2], and then
John Salerno wrote:
L.append(L) basically creates this, I think:
[1, 2, L]
Correct.
Now, assuming that's correct, and since L points to the list [1, 2],
wrong. You just said it yourself: L is now the list [1, 2, L]
why
can't '[1, 2]' be substituted for the 'L' and then the list is
Carsten Haese wrote:
L is [1,2] before the append. After the append, L is [1,2,L], which is
[1,2,[1,2,L]], which is [1,2,[1,2,[1,2,L]]] etc into infinity. L
literally contains itself after the append.
Ah, this perfectly explains it now! I guess I was dancing around this
fact, but now that
