Tuvas wrote:
> Let's say I make a program something like follows:
>
> x=[]
> x.append([1,2,3])
> x.append([4,5,6])
> print x
> print x[0]
> print x[0][1]
> x[0][1]=5
>
> Okay, everything works here as expected except the last line. Why won't
> this work? Thanks for the help!
>
Works for me, do you have more informations?
>>> x = list()
>>> x.append([1,2,3])
>>> x.append([4,5,6])
>>> print x
[[1, 2, 3], [4, 5, 6]]
>>> print x[0]
[1, 2, 3]
>>> print x[0][1]
2
>>> x[0][1] = 5
>>> print x[0][1]
5
>>>
Now if you're really using tuples, that last line won't work because
tuples are immutable e.g. you can't modify a tuple's elements after the
tuple's creation
>>> y = list()
>>> y.append((1,2,3))
>>> y.append((4,5,6))
>>> print y
[(1, 2, 3), (4, 5, 6)]
>>> print y[0]
(1, 2, 3)
>>> print y[0][1]
2
>>> y[0][1] = 5
Traceback (most recent call last):
File "<pyshell#16>", line 1, in -toplevel-
y[0][1] = 5
TypeError: object does not support item assignment
>>>
And the reason is explicitly stated (tuples don't support item assignment)
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