Python OOP实现Employee抽象类实例化报错求助

• 核心错误1：你定义的Employee类继承了ABC类，且内部有被@abstractmethod装饰的抽象方法getLeaveEntitlement，这类抽象类本身就不允许直接实例化，必须先定义子类继承Employee，并在子类中实现所有抽象方法后，才能实例化子类对象。
• 错误2：实例化时传参顺序和__init__定义的参数顺序不匹配：__init__的参数顺序是(employeeId, name, workFromHome, leaveBalance = 0)，你传入的('101', 'Jeff', 20, 'Yes')会把数值20赋值给workFromHome，字符串Yes赋值给leaveBalance，和预期的属性赋值完全错位。
• 错误3：__str__方法的输出格式和你预期的不一致，缺少ID后的冒号，另外如果需要输出WFH为No，对应传参也要调整。

方案1：不需要使用抽象类的场景（直接修改原有Employee类） #

直接移除抽象类相关的定义即可，修改后代码如下：

class Employee:
    def __init__(self, employeeId, name, leaveBalance = 0, workFromHome = 'No'):
        self._employeeId = employeeId
        self._name = name
        self._workFromHome = workFromHome
        self._leaveBalance = leaveBalance

    @property
    def employeeId(self):
        return self._employeeId
    
    @property
    def name(self):
        return self._name
    
    @property
    def workFromHome(self):
        return self._workFromHome
    @workFromHome.setter
    def workFromHome(self, atHome):
        self._workFromHome = atHome
        
    def getLeaveEntitlement(self):
        # 此处补充对应业务逻辑即可
        pass
    
    def adjustLeave(self, adjustment):
        self._leaveBalance += adjustment
        
    def __str__(self):
        # 修改输出格式匹配预期
        return f'ID: {self._employeeId} Name: {self._name} Leave Balance: {self._leaveBalance} WFH: {self._workFromHome}'
    
def main():
    # 调整传参顺序匹配参数定义
    e1 = Employee('101', 'Jeff', 20, 'No')
    print(e1)

main()

运行后输出：ID: 101 Name: Jeff Leave Balance: 20 WFH: No

方案2：需要保留抽象类作为基类的场景 #

先定义子类继承抽象基类Employee，实现抽象方法后实例化子类，代码示例如下：

from abc import ABC, abstractmethod

class Employee(ABC):
    def __init__(self, employeeId, name, leaveBalance = 0, workFromHome = 'No'):
        self._employeeId = employeeId
        self._name = name
        self._workFromHome = workFromHome
        self._leaveBalance = leaveBalance

    @property
    def employeeId(self):
        return self._employeeId
    
    @property
    def name(self):
        return self._name
    
    @property
    def workFromHome(self):
        return self._workFromHome
    @workFromHome.setter
    def workFromHome(self, atHome):
        self._workFromHome = atHome
        
    @abstractmethod
    def getLeaveEntitlement(self):
        pass
    
    def adjustLeave(self, adjustment):
        self._leaveBalance += adjustment
        
    def __str__(self):
        return f'ID: {self._employeeId} Name: {self._name} Leave Balance: {self._leaveBalance} WFH: {self._workFromHome}'

# 定义子类继承Employee，实现抽象方法
class FullTimeEmployee(Employee):
    def getLeaveEntitlement(self):
        # 示例为全职员工的年假逻辑，可根据需求调整
        return 15
    
def main():
    e1 = FullTimeEmployee('101', 'Jeff', 20, 'No')
    print(e1)

main()

运行后输出和预期完全一致。

内容的提问来源于stack exchange，提问作者Petee