[Python-Dev] PEP 461 updates

Ethan Furman ethan at stoneleaf.us
Fri Jan 17 02:51:43 CET 2014

On 01/16/2014 05:32 PM, Greg wrote:
> I don't think it matters whether the internal details of that
> debate make sense to the rest of us. The main thing is that
> a consensus seems to have been reached on bytes formatting
> being basically a good thing.

And a good thing, too, on both counts!  :)

A few folks have suggested not implementing .format() on bytes;  I've been resistant, but then I remembered that format 
is also a function.

format(value[, format_spec])

     Convert a value to a “formatted” representation, as controlled by format_spec. The interpretation of format_spec 
will depend on the type of the value argument, however there is a standard formatting syntax that is used by most 
built-in types: Format Specification Mini-Language.

     The default format_spec is an empty string which usually gives the same effect as calling str(value).

     A call to format(value, format_spec) is translated to type(value).__format__(format_spec) which bypasses the 
instance dictionary when searching for the value’s __format__() method. A TypeError exception is raised if the method is 
not found or if either the format_spec or the return value are not strings.

Given that, I can relent on .format and just go with .__mod__ .  A low-level service for a low-level protocol, what?  ;)


More information about the Python-Dev mailing list