[Python-3000] More PEP 3101 changes incoming
greg.ewing at canterbury.ac.nz
Sat Aug 11 03:57:42 CEST 2007
Ron Adam wrote:
> I'm not sure what you mean by "ditch all of these".
I was guessing that what's meant by returning a
(value, format_spec) tuple is to re-try the
formatting using the new value and spec. That's
what I thought was unnecessary, since the method
can do that itself if it wants.
> The output in this case is a null string. Setting the format spec to
> None tell the format() function not to do anything more to it.
Then why not just return an empty string?
> The format function would first call the objects __format__ method and
> give it a chance to have control, and depending on what is returned, try
> to handle it or not.
Okay, I see now -- your format function has more smarts
in it than mine.
But as was suggested earlier, returning NotImplemented
ought to be enough to signal a fallback to a different
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