Re: [Python-Dev] Subtle difference between f-strings and str.format()

28.03.18 22:05, Paul Moore пише

I can't imagine (non-contrived) code where the fact that a is formatted before b is evaluated would matter, so I'm fine with option 3.

If formatting a and evaluating b both raise exceptions, the resulting exception depends on the order. $ ./python -bb >>> a = b'bytes' >>> '{}{}'.format(a, b) Traceback (most recent call last):   File "<stdin>", line 1, in <module> NameError: name 'b' is not defined >>> f'{a}{b}' Traceback (most recent call last):   File "<stdin>", line 1, in <module> BytesWarning: str() on a bytes instance