Python中通过Mixin模式优化多继承场景下的代码复用

class Base:
    def __init__(self, args):
        self._base_args = args
        print(f"Base __init__ with {args}")

    def my_func(self, for_val):
        """Base class implementation of my_func."""
        print(f"Base's my_func called with {for_val}")
        return f"Base result for {for_val}"

class Derived(Base):
    def __init__(self, args):
        super().__init__(args)
        print(f"Derived __init__ with {args}")

# 问题所在：my_func 的实现重复
class Mock1(Base):
    def __init__(self, input_val, args):
        self._input = input_val
        super().__init__(args)
        print(f"Mock1 __init__ with input={input_val}, args={args}")

    # my_func 在 Mock1 和 Mock2 中定义完全相同
    def my_func(self, for_val):
        print(f"Mock1's my_func overriding Base. Input: {self._input}, Value: {for_val}")
        # 实际的复杂逻辑
        return f"Mock1 processed {self._input} for {for_val}"

class Mock2(Derived):
    def __init__(self, input_val, args):
        self._input = input_val
        super().__init__(args)
        print(f"Mock2 __init__ with input={input_val}, args={args}")

    # my_func 在 Mock1 和 Mock2 中定义完全相同
    def my_func(self, for_val):
        print(f"Mock2's my_func overriding Base. Input: {self._input}, Value: {for_val}")
        # 实际的复杂逻辑
        return f"Mock2 processed {self._input} for {for_val}"

# 实例化并测试
print("--- Testing original classes ---")
m1 = Mock1("data_A", "config_X")
print(m1.my_func("value_1"))

m2 = Mock2("data_B", "config_Y")
print(m2.my_func("value_2"))
print("\n")

class MyFuncMixin:
    def my_func(self, for_val):
        """
        提供 my_func 的通用实现，供其他类混合使用。
        注意：这里假设 _input 属性会在最终的类实例中存在。
        """
        print(f"Mixin's my_func called. Input: {self._input}, Value: {for_val}")
        # 实际的复杂逻辑
        return f"Mixin processed {self._input} for {for_val}"

class RefactoredMock1(MyFuncMixin, Base): # Mixin 放在 Base 之前
    def __init__(self, input_val, args):
        self._input = input_val # Mixin 方法可能需要访问此属性
        super().__init__(args)
        print(f"RefactoredMock1 __init__ with input={input_val}, args={args}")

class RefactoredMock2(MyFuncMixin, Derived): # Mixin 放在 Derived 之前
    def __init__(self, input_val, args):
        self._input = input_val # Mixin 方法可能需要访问此属性
        super().__init__(args)
        print(f"RefactoredMock2 __init__ with input={input_val}, args={args}")

# 基类定义
class Base:
    def __init__(self, args):
        self._base_args = args
        # print(f"Base __init__ with {args}")

    def my_func(self, for_val):
        """Base class implementation of my_func."""
        print(f"Base's my_func called with {for_val}")
        return f"Base result for {for_val}"

class Derived(Base):
    def __init__(self, args):
        super().__init__(args)
        # print(f"Derived __init__ with {args}")

# Mixin 类定义
class MyFuncMixin:
    def my_func(self, for_val):
        """
        提供 my_func 的通用实现，供其他类混合使用。
        注意：这里假设 _input 属性会在最终的类实例中存在。
        """
        print(f"Mixin's my_func called. Input: {self._input}, Value: {for_val}")
        # 实际的复杂逻辑
        return f"Mixin processed {self._input} for {for_val}"

# 使用 Mixin 的重构类
class RefactoredMock1(MyFuncMixin, Base):
    def __init__(self, input_val, args):
        self._input = input_val
        super().__init__(args) # 调用 Base.__init__
        print(f"RefactoredMock1 __init__ with input={input_val}, args={args}")

class RefactoredMock2(MyFuncMixin, Derived):
    def __init__(self, input_val, args):
        self._input = input_val
        super().__init__(args) # 调用 Derived.__init__ (进而调用 Base.__init__)
        print(f"RefactoredMock2 __init__ with input={input_val}, args={args}")

print("--- Testing refactored classes with Mixin ---")
rm1 = RefactoredMock1("data_C", "config_Z")
print(rm1.my_func("value_3"))
print(f"RefactoredMock1 MRO: {RefactoredMock1.__mro__}\n")

rm2 = RefactoredMock2("data_D", "config_W")
print(rm2.my_func("value_4"))
print(f"RefactoredMock2 MRO: {RefactoredMock2.__mro__}\n")