[Python-3000] PEP 3101 Updated

[Eric Smith]

Talin wrote:
> Eric Smith wrote:
>> 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.
> 
> Guido expressed a definite preference for having them be first.

I was afraid of that.  Then can we say they'll always go first?  Or is 
the intent really to say they can go anywhere (PEP says "typically placed")?

The sample implementation of vformat in the PEP says they'll go last:

               # Check for explicit type conversion
               field_spec, _, explicit = field_spec.partition("!")

Eric.