Pointers
D-Man
dsh8290 at osfmail.rit.edu
Mon Mar 20 08:35:48 EST 2000
Would I be correct if I said that Python always uses pointers and never
makes a copy of an object unless explicitly requested using copy()?
Grant Edwards wrote:
>
> On Wed, 15 Mar 2000 14:25:18 -0800, Curtis Jensen <cjensen at be-research.ucsd.edu> wrote:
>
> >I haven't found anything about pointers in python. Is there a pointer
> >type?
>
> Yes.
>
> >If so, what is the syntax?
>
> x = 3
>
> # x is now a pointer to an integer object whose value is 3.
>
> y = "asdf"
>
> # y is now a pointer to a string object whose value is "asdf".
>
> x = y
>
> # x now points to the same object as does y.
>
> z = (0,4,5)
>
> # z points to a tuple containing integer objects 0 4 and 5
>
> a = [x,y,z]
>
> # a is a pointer to a list containing the objects pointed to by x
> # y and z
>
> b = a[1]
>
> # b is a pointer to the same object pointed to by y.
>
> # and so on....
>
> All variables are pointers to objects.
>
> The tricky thing is that some objects can be changed, and some
> can not.
>
> --
> Grant Edwards grante Yow! I was in a HOT
> at TUB! I was NORMAL! I was
> visi.com ITALIAN!! I enjoyed th'
> EARTHQUAKE!
> --
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