[Python-3000] PEP 3101 update

[Talin]

Guido van Rossum wrote:
> To Talin: I'm all for a way to say blah(x, "2.2g") instead of the more
> verbose "{2.2g}".format(x). In fact it would probably be great if the
> latter was officially defined as a way to spell the former combined
> with literal text:
> 
>   "foo{2.2g}bar{3.3f}spam".format(x, y)
> 
> is shorter and mor readable than
> 
>   "foo" + blah(x, "2.2g") + "bar" + blah(y, "3.3f") + "spam"
> 
> What I object to is only the spelling of blah(x, f) as str(x, f).
> Perhaps a static string method; but probably better some other
> built-in or something in a new stdlib module.

OK, how about this:

    y.tostr("3.3f")

Essentially I'm proposing adding an overridable method named 'tostr' (or 
some better name if you can think of one) to class 'object'.

Advantages over a builtin:

   -- Doesn't add another global name
   -- Easily overridable by subclasses (gets rid of the need for a 
__format__ call in my PEP.)
   -- If we make the conversion argument optional, it could eventually 
replace the magic __str__ method.

-- Talin