python - 如何在基类中打印父类的实例？

Question

当我将类继承到 Sports 并在 init 方法中定义值时，我能够打印 Class Student 的名称。但我无法弄清楚如何打印创建学生类时给出的名称而不在运动类中定义名称，

当我在创建对象时注释掉Student.__init__(self, 1, "name1", "addr1", 123456789, "[e-mail]", 1, 2021, "english") 并定义值时，我想打印出这些值。

class Student:
    def __init__(self, sid, name, addr, phno, mailid, sec, year, sub):
        self.sid = sid
        self.name = name
        self.addr = addr
        self.phno = phno
        self.mailid = mailid
        self.sec = sec
        self.year = year
        self.sub = sub

    def printStudent(self):
        print("name",self.name,"sid",self.sid,"sec",self.sec,"year",self.year,"sub",
              self.sub, "address",self.addr,"mailid",self.mailid,"phno",self.phno)


class Sports(Student):
    def __init__(self, nofsports, nofawards):
        Student.__init__(self, 1, "name1", "addr1", 123456789, "[e-mail]", 1, 2021,
                         "english")
        self.nofsports = nofsports
        self.nofawards = nofawards

    def printSports(self):
        print("name", self.name)


s1 = Student(2,"name2","addr2",1221232332,"[e-mail]",1,2020,"math")

s2 = Sports(2, 2)
s2.printSports()

当我在创建对象时注释掉Student.__init__(self, 1, "name1", "addr1", 123456789, "[e-mail]", 1, 2021, "english") 并定义值时，我想打印出这些值。

顺便说一句，我正在学习继承和 python 的新手，我不明白为什么 python 不能打印Student我继承的类的实例，可能是因为它不是类属性？请告诉我...

标签： pythonoopinheritance

Answer 1

通常，子类__init__方法采用其超类的所有参数，以及子类需要的任何附加参数。然后它可以将公共参数传递给超类的__init__方法。

class Sports(Student):
    def __init__(self, sid, name, addr, phno, mailid, sec, year, sub, nofsports, nofawards):
        super().__init__(sid, name, addr, phno, mailid, sec, year, sub)
        self.nofsports = nofsports
        self.nofawards = nofawards

    def printSports(self):
        print("name", self.name)

s2 = Sports(1, "name1", "addr1", 123456789, "[e-mail]", 1, 2021, "english", 2, 2)