I expected the custom Formatter to behave the same as the normal "".format() function, but unnamed args or not supported.
Below is an example, which fails at a KeyError.


from string import Formatter

class test():
    def __init__(self):
        self.msg = "OK"
t = test()

print("Normal format() is {.msg}".format(t))

f = Formatter()
print(f.format("Formatter.format() is {.msg}", t))