I'm still not convinced. In order to write the string portion of the code, I need to know the names of the variables in play and I have to order them in them in some order in the string regardless.

So I still don't think

    "A is {a}, C is {c}, B is {b}".format(**locals())

is better than

   "A is {}, C is {}, B is {}".format(a, c, b)