Professor's answer to Python homework will not run: TypeError: init() missing 1 required positional argument: 'gender'

Question

我确定之前有人问过这个问题，但我还没有达到可以理解其他问题如何回答我的水平。有人可以解释这段代码的问题吗？我看不到它：

class Person:
    name = ''
    age = 0
    gender = ''

    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender


class Employee(Person):
    title = ''
    salary = 0

    def __init__(self, name, age, gender, title, salary):
        Person.__init__(name, age, gender)
        self.title = title
        self.salary = salary


George = Employee("George", 30, "Male", "Manager", 50000)
print("George's info is: Name is %s, Age is %d, Gender is %s, Title is %s, and Salary is %d" % (
George.name, George.age, George.gender, George.title, George.salary))

PyCharm返回的错误是：

Traceback (most recent call last):
  File "/Users/Sam/PycharmProjects/HW7/HW7-q2_Profs-Solution.py", line 22, in <module>
    George = Employee("George", 30, "Male", "Manager", 50000)
  File "/Users/DrewAndMon/PycharmProjects/HW7/HW7-q2_Profs-Solution.py", line 17, in __init__
    Person.__init__(name, age, gender)
TypeError: __init__() missing 1 required positional argument: 'gender'

Process finished with exit code 1

Answer 1

需要改的是classEmployee中对Person.__init__(name, age, gender)的调用，定义上是def __init__(self, name, age, gender):
您的正确密码是-

class Person:
    name = ''
    age = 0
    gender = ''

    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender


class Employee(Person):
    title = ''
    salary = 0

    def __init__(self, name, age, gender, title, salary):
        Person.__init__(self, name, age, gender)
        self.title = title
        self.salary = salary


George = Employee("George", 30, "Male", "Manager", 50000)
print("George's info is: Name is %s, Age is %d, Gender is %s, Title is %s, and Salary is %d" % (
George.name, George.age, George.gender, George.title, George.salary))

这会给你你的输出-

George's info is: Name is George, Age is 30, Gender is Male, Title is Manager, and Salary is 50000

Answer 2

更改此行：

        Person.__init__(name, age, gender)

至：

        Person.__init__(self, name, age, gender)

说明：Person.__init__方法有四个参数，第一个是被初始化对象的self参数。通常，self 参数的特殊之处在于它会自动获取调用该方法的对象的值。但是，由于 Person 是 class，而不是对象，在这种情况下，该方法不是在对象上调用的，因此 self 参数必须作为显式参数传递。

这样写比较正常：

        super().__init__(name, age, gender)

这看起来有点奇怪，但它避免了不必要地第二次写父 class 的名字，并且当 class 有两个 superclass 时它可以正常工作.

Professor's answer to Python homework will not run: TypeError: init() missing 1 required positional argument: 'gender'

Professor's answer to Python homework will not run: TypeError: init() missing 1 required positional argument: 'gender'

oop

python-3.6

Professor's answer to Python homework will not run: TypeError: __init__() missing 1 required positional argument: 'gender'

Professor's answer to Python homework will not run: TypeError: __init__() missing 1 required positional argument: 'gender'

oop

python-3.6

Professor's answer to Python homework will not run: TypeError: init() missing 1 required positional argument: 'gender'

Professor's answer to Python homework will not run: TypeError: init() missing 1 required positional argument: 'gender'