class A:
def a(self, params):
print("I from a, params is {}".format(params))
@staticmethod
def b(params):
print("I from b, params is {}".format(params))
@classmethod
def c(cls, params):
print("I from c, params is {}".format(params))
def d(params):
print("I from d, params is {}".format(params))
demo = A()
getattr(demo, "a")("a")
getattr(A, "b")("b")
getattr(A, "c")("c")
setattr(demo, "d", d)
getattr(demo, "d")("d")