使用 mypy 对 Protocol 子类的 python 函数签名进行类型判断

有没有一种方法可以安全地判断派生协议的python类的类型？

如果我使用某个方法函数签名定义协议，则隐式子类必须定义具有兼容签名的方法:

# protocols.py

from abc import abstractmethod
from dataclasses import dataclass
from typing import Protocol

class SupportsPublish(Protocol):
    @abstractmethod
    def publish(self, topic: str):
        ...

def publish(m: SupportsPublish):
    m.publish("topic")

@dataclass
class Publishable:
    foo: str = "bar"

    def publish(self):
        print(self)

publish(Publishable())

# ✗ mypy protocols.py       
# protocols.py:24: error: Argument 1 to "publish" has incompatible type "Publishable"; expected "SupportsPublish"  [arg-type]
# protocols.py:24: note: Following member(s) of "Publishable" have conflicts:
# protocols.py:24: note:     Expected:
# protocols.py:24: note:         def publish(self, topic: str) -> Any
# protocols.py:24: note:     Got:
# protocols.py:24: note:         def publish(self) -> Any
# Found 1 error in 1 file (checked 1 source file)

但是，如果我显式地子类型SupportsPublish，mypy不会报告类型错误:

...
@dataclass
class Publishable(SupportsPublish):
...

# ✗ mypy protocols.py
# Success: no issues found in 1 source file

基于来自PEP的this blurb，我预计类型判断器会发现函数签名不匹配:

请注意，显式和隐式子类型之间几乎没有区别，显式子类化的主要好处是"免费"获得一些协议方法.此外，类型判断器可以静态地验证类是否确实正确地实现了协议:

这就是我的环境:

> mypy --version
mypy 1.3.0 (compiled: yes)
> python --version
Python 3.9.17

我以为mypy会指出函数签名不匹配的问题.