New-style string formatting

[Mel Wilson]

In article <mailman.1053447752.25340.python-list at python.org>,
Skip Montanaro <skip at pobox.com> wrote:
>    Gerrit> What Alexander proposes and I support is not to do string
>    Gerrit> interpolation, but to simply change the syntax because the '%'
>    Gerrit> is redundant; it's a much smaller change:
>    Gerrit> "bla %s blo %d" % ("blu", 42) # becomes
>    Gerrit> "bla %s blo %d" ("blu", 42)

>Just because it's not a big change doesn't mean it's worthwhile.  Here are
>a couple counterarguments: [ ... ]
>    * This idea doesn't extend to dictionary interpolation (without a change
>      to the language syntax), which for interpolations with many arguments
>      is less error-prone because you specifically indicate what value to
>      insert where instead of relying on positional correctness.

   Actually, it probably would, via

        "%d %g %r%s" (*list_of_things())
and
        "%(a1)d %(a2)g %(a3)r%(a4)s" (**some_dictionary)

   but I still don't like it enough, for the other reasons
you give, and the fact that it pre-empts callability for any
user-defined string-like object.  One way to do the same thing
means that class authors only have to implement those one ways
to have done Right by the standard implementation.

        Regards.        Mel.