[PyKDE] Deep copy

[Phil Thompson]

On Tuesday 22 July 2003 2:18 am, Vio wrote:
> Hi,
> I need to implement copy/cut/paste of whole Pyqt objects. This
> apparently requires 'deep copies' of a target object: one initial copy
> used as the 'clipboard' object (my cookie-cutter), then all other copies
> created by 'deep-copying' the clipboard object.
>
> Now is there an easy way to make 'deep copies' of PyQt objects? The
> assignment operator '=' only makes so-called 'shallow' copies, which are
> simple references to an object. I need real duplicate objects, which are
> independent of each other (modifying one copy should have no affects on
> the other copies).
>
> So what are my options besides manually reconstructing the object
> (calling the PyQt constructor and copying each data element into the new
> instance sounds costly)? And python's 'copy' module unfortunately chokes
> on objects:
> "copy.deepcopy(obj)" bombs unfortunately:(
>
> Or are there better ways of achieving this.

You can't do it. For one thing, there is no mechanism to invoke the copy ctor 
of the underlying C++ instance. Secondly many (most?) Qt classes are designed 
not to be copied - they have declared private copy ctors and assignment 
operators.

Phil