[Python-Dev] transitioning from % to {} formatting

[Benjamin Peterson]

2009/10/4 INADA Naoki <songofacandy at gmail.com>:
> What about using string prefix 'f'?
>
>  f"{foo} and {bar}" % something == "{foo} and {bar}.format(something)
>
>  s = f"{foo}"
>  t = "%(bar)s"
>  s + t  # raises Exception
>
> Transition plan:
> n: Just add F prefix. And adding "format_string" in future.
> n+1: deprecate __mod__() without 'F'.
> n+2: libraries use .format() and deprecate __mod__() with 'F'
> n+3: remove __mod__()

-1 That requires keeping formatting information around in every string instance.


-- 
Regards,
Benjamin