[Python-3000] Nix dict.copy()

[Brett Cannon]

On Feb 8, 2008 5:03 PM, Guido van Rossum <guido at python.org> wrote:
> On Feb 8, 2008 4:51 PM, Raymond Hettinger <python at rcn.com> wrote:
> > I recommend dropping the dict.copy() method from Py3.0.
> >
> > * We can already write:  newd = copy.copy(d).
> > * We can also write:     newd = dict(d)
> > * Both of those approaches also work for most other containers.
> > * The collections.Mapping ABC does not support copy().
> > * copy() is not a universal feature of mapping like objects
> > * Lists do not have a copy() method.
> > * If we drop dict.copy(), I'll can also drop set.copy() which is unneeded.
> >
> > Let's make the basic APIs as clean and parallel as possible.
>
> Makes sense.  I request that you also implement the transitional code:
> either a fixer for 2to3 or (perhaps more realistically) a warning to
> dict.copy() when -3 is given.

+1 on the warning over the fixer. Since 2to3 can't do it perfectly I
think it would be better to let users deal with it directly.

-Brett