Python：具有只讀屬性的協議元類

Question

我想實現一個具有只讀屬性並減少樣板文件的協議。 簡而言之：

# I want to reduce boilerplate of the following.
class MyVerboseProtocol(Protocol)
    @property
    def x(self):
        return x


# I want this to be functionally equivalent to MyVerboseProtocol
class MyProtocol(Protocol)
     x # this should be read-only


class MyClass(MyProtocol)
    x = 5


my_class = MyClass()
print(my_class.x) # should print 5
myclass.x = 4 # should raise some exception

我嘗試了一個元類，但是帶有協議的東西使該屬性不是只讀的：

class MyMetaProtocol(type(Protocol) # needs type(Protocol) or something won't resolve
    @property
    def x(self): # pylance seems to want self here
        return self.x


class MyProtocol(Protocol, metaclass=MyMetaProtocol)
    x


class MyClass(MyProtocol)
    x = 5


my_class = MyClass()
print(my_class.x) # should print 5
myclass.x = 4 # seems fine??

Answer 1

我要去 go，“越簡單越好”。 違反協議背后的直覺可能不值得節省幾次按鍵。

另一個選項是 class 裝飾器，但如果我們有能力首先修改 class，那么它似乎沒有多大意義。