如何让 str 或 repr return 成为当前 class 的名字？

Question

我有这个代码：

class Employee:
    def __init__(self, name, pay, gender):
        self.name = name
        self.pay = pay
        self.gender = gender

    def add_raise(self):
        self.pay = int(self.pay*1.10)

    def __str__(self):
        if self.gender == "Female" or self.gender == "female":
            return f"{__class__.__name__} name: {self.name}, and she earns {self.pay} Pound"
        else:
            return f"{__class__.__name__} name: {self.name}, and he earns {self.pay} Pound"

    def __repr__(self):
        if self.gender == "Female" or self.gender == "female":
            return f"{__class__.__name__} name: {self.name}, and she earns {self.pay} Pound"
        else:
            return f"{__class__.__name__} name: {self.name}, and he earns {self.pay} Pound"

class Supervisor(Employee):
    def __init__(self, name, pay, gender, department):
        super().__init__(name, pay, gender)
        self.department = department

现在，当我尝试运行

emp1 = Employee("Ron", 1000, "male")
emp10 = Supervisor("Hermoine", 3000, "female", "General")
print(emp1, emp10)

我只得到“员工姓名”开头。我如何更改它以反映“Hermoine”是一个 Supervisor 而不仅仅是一个 Employee，而不重写 __str__ 和 __repr__ 方法？

Answer 1

解决方案：

尝试将您的第一个 class 更改为：

class Employee:
    def __init__(self, name, pay, gender):
        self.name = name
        self.pay = pay
        self.gender = gender

    def add_raise(self):
        self.pay = int(self.pay*1.10)

    def __str__(self):
        if self.gender == "Female" or self.gender == "female":
            return f"{self.__class__.__name__} name: {self.name}, and she earns {self.pay} Pound"
        else:
            return f"{self.__class__.__name__} name: {self.name}, and he earns {self.pay} Pound"

    def __repr__(self):
        if self.gender == "Female" or self.gender == "female":
            return f"{self.__class__.__name__} name: {self.name}, and she earns {self.pay} Pound"
        else:
            return f"{self.__class__.__name__} name: {self.name}, and he earns {self.pay} Pound"

尝试在所有字符串中使用 self.__class__.__name__ 而不是 __class__.__name__。

现在：

emp1 = Employee("Ron", 1000, "male")
emp10 = Supervisor("Hermoine", 3000, "female", "General")
print(emp1, emp10)

输出：

Employee name: Ron, and he earns 1000 Pound Supervisor name: Hermoine, and she earns 3000 Pound

解释：

self returns 实际 class 名称的原因是因为它将从当前 self 实例中提取 class 名称。没有 self 只会得到原始父 class 的 class 名称，而不是它当前所在的实际 class，这就是 self 如此重要的原因。

正如@MadPhysicist 提到的那样，这是“因为 __class__ 在 class 执行时的词法作用域”。

如何让 str 或 repr return 成为当前 class 的名字？

How can I make str or repr return the current class's name?

python

python-3.x

class

python-class

解决方案：

解释：

如何让 __str__ 或 __repr__ return 成为当前 class 的名字？

How can I make __str__ or __repr__ return the current class's name?

python

python-3.x

class

python-class

解决方案：

解释：

如何让 str 或 repr return 成为当前 class 的名字？

How can I make str or repr return the current class's name?