Python中通过Mixin模式解决多继承路径下的方法复用问题

class Base:
    """基础类，可能定义了一些通用接口或属性"""
    def __init__(self, args):
        self.base_args = args
        print(f"Base __init__ with {args}")

    def common_method_in_base(self):
        print("Method from Base")

class Derived(Base):
    """派生自Base的类，可能添加了特有的行为"""
    def __init__(self, args):
        super().__init__(args)
        print(f"Derived __init__ with {args}")

    def specific_method_in_derived(self):
        print("Method from Derived")

# 两个不同的派生类，它们继承路径不同
class Mock1(Base):
    def __init__(self, input_data, args):
        super().__init__(args) # 调用Base的构造函数
        self._input = input_data
        print(f"Mock1 __init__ with {input_data}")

    # my_func 在这里实现
    def my_func(self, for_val):
        """这是一个在Mock1中定义的通用功能"""
        print(f"Mock1's my_func executing for: {for_val} with input: {self._input}")
        # 实际的业务逻辑

class Mock2(Derived):
    def __init__(self, input_data, args):
        super().__init__(args) # 调用Derived的构造函数
        self._input = input_data
        print(f"Mock2 __init__ with {input_data}")

    # my_func 在这里实现，与Mock1中的实现完全相同
    def my_func(self, for_val):
        """这是一个在Mock2中定义的通用功能，与Mock1相同"""
        print(f"Mock2's my_func executing for: {for_val} with input: {self._input}")
        # 实际的业务逻辑

class MyFuncMixin:
    """
    提供 my_func 方法的Mixin类。
    它封装了 my_func 的通用实现。
    """
    def my_func(self, for_val):
        # 共享的实现逻辑
        # 注意：Mixin类可以访问宿主类的属性，例如 self._input
        # 但通常建议Mixin本身不定义状态，而是操作宿主类的状态。
        print(f"MyFuncMixin's my_func executing for: {for_val} with input: {getattr(self, '_input', 'N/A')}")
        # 实际的业务逻辑

class Mock1(MyFuncMixin, Base): # Mixin放在Base之前
    def __init__(self, input_data, args):
        super().__init__(args) # 调用MRO中的下一个__init__，这里是Base.__init__
        self._input = input_data
        print(f"Mock1 __init__ with {input_data}")

class Mock2(MyFuncMixin, Derived): # Mixin放在Derived之前
    def __init__(self, input_data, args):
        super().__init__(args) # 调用MRO中的下一个__init__，这里是Derived.__init__
        self._input = input_data
        print(f"Mock2 __init__ with {input_data}")

print("--- 实例化 Mock1 ---")
m1 = Mock1("data_for_mock1", "args_for_base")
m1.my_func("value_A")
m1.common_method_in_base() # 依然可以访问Base的方法

print("\n--- 实例化 Mock2 ---")
m2 = Mock2("data_for_mock2", "args_for_derived")
m2.my_func("value_B")
m2.specific_method_in_derived() # 依然可以访问Derived的方法
m2.common_method_in_base() # 依然可以访问Base的方法 (通过Derived继承)

--- 实例化 Mock1 ---
Base __init__ with args_for_base
Mock1 __init__ with data_for_mock1
MyFuncMixin's my_func executing for: value_A with input: data_for_mock1
Method from Base

--- 实例化 Mock2 ---
Base __init__ with args_for_derived
Derived __init__ with args_for_derived
Mock2 __init__ with data_for_mock2
MyFuncMixin's my_func executing for: value_B with input: data_for_mock2
Method from Derived
Method from Base