基于@mkorpela的精彩回答，我写了一个类似的包(ipromise pypi github)，它做了更多的检查:

假设A继承了B和C, B继承了C。

模块ipromise检查:

If A.f overrides B.f, B.f must exist, and A must inherit from B. (This is the check from the overrides package). You don't have the pattern A.f declares that it overrides B.f, which then declares that it overrides C.f. A should say that it overrides from C.f since B might decide to stop overriding this method, and that should not result in downstream updates. You don't have the pattern A.f declares that it overrides C.f, but B.f does not declare its override. You don't have the pattern A.f declares that it overrides C.f, but B.f declares that it overrides from some D.f.

它还具有用于标记和检查实现抽象方法的各种特性。

Python不是Java。当然，没有真正的编译时检查。

我认为文档字符串中的注释就足够了。这允许您的方法的任何用户输入help(obj.method)，并看到该方法是一个覆盖。

你也可以用类Foo(interface)显式地扩展一个接口，这将允许用户输入help(interface .method)来了解你的方法想要提供的功能。

Hear是最简单的，可以在Jython下使用Java类:

class MyClass(SomeJavaClass):
     def __init__(self):
         setattr(self, "name_of_method_to_override", __method_override__)

     def __method_override__(self, some_args):
         some_thing_to_do()

在python 3.6及以上版本中，@override提供的功能可以使用python的描述符协议轻松实现，即set_name dunder方法:

class override:
    def __init__(self, func):
       self._func = func
       update_wrapper(self, func)

    def __get__(self, obj, obj_type):
        if obj is None:
            return self
        return self._func

    def __set_name__(self, obj_type, name):
        self.validate_override(obj_type, name)

    def validate_override(self, obj_type, name):
        for parent in obj_type.__bases__:
            func = parent.__dict__.get(name, None)
            if callable(func):
                return
        else:
            raise NotImplementedError(f"{obj_type.__name__} does not override {name}")

注意，这里的set_name是在定义包装类之后调用的，我们可以通过调用包装类的dunder方法基来获得它的父类。

对于它的父类，我们希望检查包装的函数是否在类中通过实现

检查函数名是否在类字典中 它是可调用的

使用i就像这样简单:

class AbstractShoppingCartService:
    def add_item(self, request: AddItemRequest) -> Cart:
        ...


class ShoppingCartService(AbstractShoppingCartService):
    @override
    def add_item(self, request: AddItemRequest) -> Cart:
        ...

您可以使用来自PEP 544的协议。使用这种方法，接口实现关系只在使用站点声明。

假设您已经有了一个实现(让我们称之为MyFoobar)，您定义了一个接口(一个协议)，它具有实现的所有方法和字段的签名，我们称之为IFoobar。

Then, at the use site, you declare the implementation instance binding to have the interface type e.g. myFoobar: IFoobar = MyFoobar(). Now, if you use a field/method that is missing in the interface, Mypy will complain at the use site (even if it would work at runtime!). If you failed to implement a method from the interface in the implementation, Mypy will also complain. Mypy won't complain if you implement something that doesn't exist in the interface. But that case is rare, since the interface definition is compact and easy to review. You wouldn't be able to actually use that code, since Mypy would complain.

现在，这还不包括在父类和实现类中都有实现的情况，比如ABC的一些使用。但是在Java中使用override，即使在接口中没有实现。这个解决方案适用于这种情况。

from typing import Protocol

class A(Protocol):
    def b(self):
        ...
    def d(self):  # we forgot to implement this in C
        ...

class C:
    def b(self):
        return 0

bob: A = C()

输入检查结果:

test.py:13: error: Incompatible types in assignment (expression has type "C", variable has type "A")
test.py:13: note: 'C' is missing following 'A' protocol member:
test.py:13: note:     d
Found 1 error in 1 file (checked 1 source file)

即兴对@mkorpela的伟大回答，这里有一个版本

更精确的检查、命名和引发的Error对象

def overrides(interface_class):
    """
    Function override annotation.
    Corollary to @abc.abstractmethod where the override is not of an
    abstractmethod.
    Modified from answer https://stackoverflow.com/a/8313042/471376
    """
    def confirm_override(method):
        if method.__name__ not in dir(interface_class):
            raise NotImplementedError('function "%s" is an @override but that'
                                      ' function is not implemented in base'
                                      ' class %s'
                                      % (method.__name__,
                                         interface_class)
                                      )

        def func():
            pass

        attr = getattr(interface_class, method.__name__)
        if type(attr) is not type(func):
            raise NotImplementedError('function "%s" is an @override'
                                      ' but that is implemented as type %s'
                                      ' in base class %s, expected implemented'
                                      ' type %s'
                                      % (method.__name__,
                                         type(attr),
                                         interface_class,
                                         type(func))
                                      )
        return method
    return confirm_override

下面是它在实践中的样子:

NotImplementedError未在基类中实现

class A(object):
    # ERROR: `a` is not a implemented!
    pass

class B(A):
    @overrides(A)
    def a(self):
        pass

会导致更具有描述性的NotImplementedError错误

function "a" is an @override but that function is not implemented in base class <class '__main__.A'>

完整的堆栈

Traceback (most recent call last):
  …
  File "C:/Users/user1/project.py", line 135, in <module>
    class B(A):
  File "C:/Users/user1/project.py", line 136, in B
    @overrides(A)
  File "C:/Users/user1/project.py", line 110, in confirm_override
    interface_class)
NotImplementedError: function "a" is an @override but that function is not implemented in base class <class '__main__.A'>

NotImplementedError“期望实现的类型”

class A(object):
    # ERROR: `a` is not a function!
    a = ''

class B(A):
    @overrides(A)
    def a(self):
        pass

会导致更具有描述性的NotImplementedError错误

function "a" is an @override but that is implemented as type <class 'str'> in base class <class '__main__.A'>, expected implemented type <class 'function'>

完整的堆栈

Traceback (most recent call last):
  …
  File "C:/Users/user1/project.py", line 135, in <module>
    class B(A):
  File "C:/Users/user1/project.py", line 136, in B
    @overrides(A)
  File "C:/Users/user1/project.py", line 125, in confirm_override
    type(func))
NotImplementedError: function "a" is an @override but that is implemented as type <class 'str'> in base class <class '__main__.A'>, expected implemented type <class 'function'>

@mkorpela answer的伟大之处在于检查发生在初始化阶段。检查不需要“运行”。参考前面的例子，类B从未初始化(B())，但NotImplementedError仍然会引发。这意味着可以更快地捕获覆盖错误。