我无法确定遗漏的论点

Question

我试图编写一个代码来显示对象User1的特权列表

class User:
def __init__(self, f_name, l_name, age):
    self.f_name = f_name
    self.l_name = l_name
    self.age = age

def describe(self):
    print(f"The user {self.f_name} {self.l_name} has {self.age} years old person.")

def greet(self):
    print(f"Hi {self.f_name}, you are the Administer right now!")

class Privileges:
    def __init__(self, privileges):
        self.privileges = ['add post', 'del post', 'ban users']

    def show_privileges(self):
    print(f"These are the Admin list of privileges: {self.privileges}.")

class Admin(User):
    def __init__(self, f_name, l_name, age):
        super().__init__(f_name, l_name, age)
        self.privileges = Privileges()

user1 = Admin('Porco', 'Rosso', 42)
user1.privileges.show_privileges()

这是输出，但我找不到缺少的参数：

    Traceback (most recent call last):
      File "C:\Users\Administrator\Desktop\python_work\teste34.py", line 25, in <module>
        user1 = Admin('Porco', 'Rosso', 42)
      File "C:\Users\Administrator\Desktop\python_work\teste34.py", line 23, in __init__
        self.privileges = Privileges()
    TypeError: __init__() missing 1 required positional argument: 'privileges'
    [Finished in 0.433s]

我想用我以前做过的一个代码来补充，在这里不需要传递参数：

    class User:
def __init__(self, f_name, l_name, age):
    self.f_name = f_name
    self.l_name = l_name
    self.age = age

def describe(self):
    print(f"The user {self.f_name} {self.l_name} has {self.age} years old person.")

def greet(self):
    print(f"Hi {self.f_name}, you are now the Admin!")

    class Admin(User):
        def __init__(self, f_name, l_name, age):
    super().__init__(f_name, l_name, age)
    self.privileges = ['add post', 'del post', 'ban users']

def show_privileges(self):
    print(f"These are SysOp list of privileges: {self.privileges}.")

    user1 = Admin('Porco', 'Rosso', 42)
    user1.describe()
    user1.greet()
    user1.show_privileges()

Answer 1

    self.privileges = Privileges()

不传递任何参数

class Privileges:
    def __init__(self, privileges):

要求一个名为privileges的参数。但它从未使用过它，所以您可能只需要删除它，使其：

class Privileges:
    def __init__(self):

如果它应该有一个默认值，那么您需要如下内容：

类别特权： definit（self，privileges=（'add post'，'del post'，'ban users'））： self.privileges=列表（特权）

请注意，如果用户传递了自己的list（您不希望您的修改影响他们，反之亦然），您可以对传递的内容进行浅层复制，以避免mutable default arguments问题和类似问题

Answer 2

根据您的评论，您的意思是隐式地传递类Priviliges的__init__中的参数。为此，您需要一个默认参数：

class User:
    def __init__(self, f_name, l_name, age):
        self.f_name = f_name
        self.l_name = l_name
        self.age = age

def describe(self):
    print(f"The user {self.f_name} {self.l_name} has {self.age} years old person.")

def greet(self):
    print(f"Hi {self.f_name}, you are the Administer right now!")

class Privileges:
    def __init__(self, privileges = ['add post', 'del post', 'ban users']):
        self.privileges = privileges

    def show_privileges(self):
        print(f"These are the Admin list of privileges: {self.privileges}.")

class Admin(User):
    def __init__(self, f_name, l_name, age):
        super().__init__(f_name, l_name, age)
        self.privileges = Privileges()

user1 = Admin('Porco', 'Rosso', 42)
user1.privileges.show_privileges()

输出：

These are the Admin list of privileges: ['add post', 'del post', 'ban users'].

注意

但是，强烈反对使用可变类型作为默认参数