python decorator with exec()

class A:
    def b(self, n):
        def deco(fun):
            def deco_sub(*args, **kwargs):
                print(f'--deco begin with b({n})')
                fun(*args, **kwargs)

            return deco_sub

        return deco


a0 = A()
a1 = A()
a2 = A()


@a0.b(11)
def m0(v):
    print(str(m0))
    print(v)


@a1.b(13)
def m1(v):
    print(str(m1))
    print(v)


@a2.b(17)
def m2(v):
    print(str(m2))
    print(v)


m0(10)
m1(11)
m2(12)

for i in range(3):
    exec(f'''@a{i}.b(1)
def m{i}(v):
    print(str(m{i}))
    print(v * 100)
''')

m0(10)
m1(11)
m2(12)