def arg_test(x, y, z):
        print("x = %s, y = %s, z = %s\n" % (x,y,z))
        return None

arg_test(1,2,3)

# test keyword arguments
arg_test(y=2,z=3,x=1)

# test dictionary supplied arguments
data = {"y": 2, "z" : 3, "x" : 1}
arg_test(**data)