Collin Jones wrote:
> Hello,
>
> Is there a Python equivalent to creating "reference" or "pointer"-type
> variables as in C++?? I'm trying to create a couple classes that have
> something like a container-and-iterator relationship; one class acts as
> a data resource (container-like) and can be queried by multiple control
> classes if needed (iterator-like).
>
> If it's of any use, one class will contain all the frames of an
> animation and its attributes, and the other will query the former for
> image data and those attributes but control the actual animation process
> on its own.
>
> Here is a simple (albeit crappily written) example, in C++, of what I'm
> trying to achieve. Perhaps in Python I should be using a different
> paradigm than this... that would be fine, as long as I can figure out
> something that will serve my purpose.
>
> #include <iostream>
> using namespace std;
>
> class CrazyRes {
> private:
> char *astring, *bstring;
> public:
> void setAString(char *s);
> void setBString(char *s);
> char *getAString() { return astring; }
> char *getBString() { return bstring; }
> };
> void CrazyRes::setAString(char *s)
> {
> astring = new char[255];
> strcpy(astring, s);
> }
> void CrazyRes::setBString(char *s)
> {
> bstring = new char[255];
> strcpy(bstring, s);
> }
>
> class CrazyCtrl {
> private:
> CrazyRes *res;
> public:
> void attach(CrazyRes *r) { res = r; }
> void printAString() { cout << res->getAString(); }
> void printBString() { cout << res->getBString(); }
> };
>
> int main()
> {
> CrazyRes res;
> CrazyCtrl ctrl;
>
> res.setAString("Hey! A-String!\n");
> res.setBString("Whoa! B-String!\n");
>
> ctrl.attach(&res);
> ctrl.printAString();
> ctrl.printBString();
>
> return 0;
> }
>
> I tried to keep this to the point... thanks in advance for any suggestions.
>
Basically names are bound to values by reference in Python - a name, or
an item in a "container" such as a list or a dictionary, is simply a
reference to a value. Assignment binds a new item or name to an existing
value.
regards
Steve
--
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Holden Web LLC www.holdenweb.com
PyCon TX 2006 www.python.org/pycon/
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