class test1(object):
    def __init__(self, name, pwd):
        self.name = name
        self.pwd = pwd
        self.z = 0

    def sub(self):
        z = self.name + self.pwd
        self.z = z
        self.pr(z)

    def pr(self, z):
        print("z:%s" % z)

    def jian(self):
        xx = self.z - 2
        print("xx:%s" % xx)
        print(self.z)


z = test1(1, 2)
z.sub()
z.jian()