[Python-3000] PEP 3101 Updated

[Eric Smith]

James Thiele wrote:
> The section on the explicit conversion flag contains the following line:
> 
>       These flags are typically placed before the format specifier:
> 
> Where else can they be placed?

I'd like this to say they can only be placed where the PEP describes 
them, or maybe to be only at the end.
"{0!r:20}".format("Hello")
or
"{0:20!r}".format("Hello")

Putting them at the end makes the parsing easier, although I grant you 
that that's not a great reason for specifying it that way.  Whatever it 
is, I think there should be only one place they can go.

> Also there is no description of what action (if any) is taken if an
> unknown explicit conversion flag is encoubtered.

I would assume a ValueError, but yes, it should be explicit.