I think bf'...' should be compared to b'...' % rather than to f'...'. IOW bf'...' is to f'...' as b'...'% is to '...'%. On Wed, Oct 7, 2015 at 5:34 AM, Andrew Barnert <abarnert@yahoo.com> wrote:
On Oct 7, 2015, at 04:35, Nick Coghlan <ncoghlan@gmail.com> wrote:
On 4 October 2015 at 08:25, Andrew Barnert <abarnert@yahoo.com> wrote: Nick's suggestion of having it do %-formatting makes sense. Yes, it
that {count:03} is an error and you need '{count:03d}', which is inconsistent with f-strings. But that seems like a much less serious
means problem
than bytes formatting not being able to handle bytes.
Exactly, if someone is mistakenly thinking bf"{header}{content}{footer}" is equivalent to f"{header}{content}{footer}".encode(), they're likely to get immediate noisy errors when they start trying to format fields.
Except that multiple people in this thread are saying that'd exactly what it should mean (which I think is a very bad idea).
The parallel I'd attempt to draw is that:
f"{header}{content}{footer}" is to "{}{}{}".format(header, content, footer)
as:
bf"{header:b}{content:b}{footer:b}" would be to b"%b%b%b" % (header, content, footer)
To make the behaviour clearer in the latter case, it may be reasonable to *require* an explicit field format code, since that corresponds more closely to the mandatory field format codes in mod-formatting.
Are you suggestive that if a format specifier is given, it must include the format code (which seems perfectly reasonable to me--guessing that :3 means %3b is likely to be wrong more often than it's right…), or that a format specifier must always be given, with no default to :b (which seems more obtrusive and solves less of a problem).
-- --Guido van Rossum (python.org/~guido)