is it a bug in Module copy or i am wrong??

Terry Reedy tjreedy at udel.edu
Fri Nov 7 20:52:30 CET 2008


yoma wrote:
> python version 2.5 in module copy
> 
> we all know that copy have two method: copy() and deepcopy().
> and the explain is
> - A shallow copy constructs a new compound object and then (to the
>   extent possible) inserts *the same objects* into it that the
>   original contains.
> 
> - A deep copy constructs a new compound object and then, recursively,
>   inserts *copies* into it of the objects found in the original.

Read a little further: This module does not copy types like module, 
method, stack trace, stack frame, file, socket, window, array, or any 
similar types. It does ``copy'' functions and classes (shallow and 
deeply), by returning the original object unchanged

> so i try a example:
> import copy
> 
> class A:
>     i = 1
> 
> class B:
>     a = A()
> 
> 
> b = B()

The only attribute of b itself is .__class__ == B, which as the above 
says, is 'copied' by not being copied.  So either shallow or deep copies 
  of b will have .__class__ == the original B with its original instance 
of a.

tjr




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