On Mon, Jan 13, 2014 at 4:51 PM, Guido van Rossum <gu...@python.org> wrote:
> Terminology. Let's use the official terminology rather than making stuff > up. > > The docs at http://docs.python.org/3/library/string.html#formatspec > use the following terminology: > > Replacement field: {...}; contains field name, conversion, format spec > in that order, all optional. > > Field name: either a decimal integer (referring to an argument by > position) or an identifier (by name), or omitted (uses the next > available position). > > Conversion: !r, !s, !a; these refer to repr(), str(), ascii() to the > value, and then the format spec applies to the resulting string. > > Format spec: colon, bunch of stuff, type; the type is a letter such as > d (decimal) or s (string), and the stuff between the colon and the > type is used to specify field width, alignment, sign, padding and > such. > > > Also. {:b} means binary (i.e. numbers in base 2). I'm not sure what > this leaves for interpolating bytes if we don't want to use {:s}. The > docs at > http://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting > don't show %b so it could still be used there, but it would be nicer > to be consistent. I have been going on the assumption that bytes.format() would change what '{}' meant for itself and would only interpolate bytes. That convenient between Python 2 and 3 since it represents what we want it to (str and bytes under the hood, respectively), so it just falls through. We could also add a 'b' conversion for bytes() explicitly so as to help people not accidentally mix up things in bytes.format() and str.format(). But I was not suggesting adding a specific format spec for bytes but instead making bytes.format() just do the .encode('ascii') automatically to help with compatibility when a format spec was present. If people want fancy formatting for bytes they can always do it themselves before calling bytes.format().
_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
