[Python-ideas] Customizing format()

[Terry Reedy]

Eric Smith wrote:
> Antoine Pitrou wrote:
>> Raymond Hettinger <python at ...> writes:
>>> Am curious whether you guys like this proposal?
>>
>> I find it good for the builtin format() function, but how does it work 
>> for
>> str.format()?
> 
> I agree: I like it, but it's not enough. I use str.format() way more 
> often than I hope to ever use builtin format(). If we make any change, 
> I'd rather see it focused on the format mini-language.

I agree.  My impression was that format() was added mostly for 
consistency with the policy of having a 'public' interface to special 
methods, and that .__format__ was added to support str.format.  Hence, 
any new capability of .__format__ must be accessible from format strings 
with replacement fields.

tjr