问题

Here's the translation of the code portion you provided:

官方的Enum HOWTO有[这个示例](https://docs.python.org/3.11/howto/enum.html#planet)：

```python
class Planet(Enum):
    MERCURY = (3.303e+23, 2.4397e6)
    VENUS   = (4.869e+24, 6.0518e6)
    EARTH   = (5.976e+24, 6.37814e6)
    MARS    = (6.421e+23, 3.3972e6)
    JUPITER = (1.9e+27,   7.1492e7)
    SATURN  = (5.688e+26, 6.0268e7)
    URANUS  = (8.686e+25, 2.5559e7)
    NEPTUNE = (1.024e+26, 2.4746e7)

    def __init__(self, mass, radius):
        self.mass = mass       # in kilograms
        self.radius = radius   # in meters

    @property
    def surface_gravity(self):
        # universal gravitational constant  (m3 kg-1 s-2)
        G = 6.67300E-11
        return G * self.mass / (self.radius * self.radius)

>>> Planet.EARTH.value
(5.976e+24, 6378140.0)

>>> Planet.EARTH.surface_gravity
9.802652743337129

假设我正在做类似于这样的事情，我希望将.value，即类似于(3.303e+23, 2.4397e6)的元组，视为Planet API的不稳定实现细节。我不希望我的API使用者依赖于它们。相反，我希望他们使用我明确公开的属性，如.surface_gravity。

有没有一种传统的方法来指示这一点？

我目前只是在docstring中添加一个注释，像这样：

class Planet(Enum):
    """.value is an implementation detail. Use .surface_gravity instead."""

但这似乎太容易被忽略。

如果这是一个普通的类，我只需将其命名为._value而不是.value。但在这里，.value是自动添加的，因为我从Enum中继承，我没有看到覆盖它的方法。

<details>
<summary>英文:</summary>

The official Enum HOWTO has [this example](https://docs.python.org/3.11/howto/enum.html#planet):

```python
class Planet(Enum):
    MERCURY = (3.303e+23, 2.4397e6)
    VENUS   = (4.869e+24, 6.0518e6)
    EARTH   = (5.976e+24, 6.37814e6)
    MARS    = (6.421e+23, 3.3972e6)
    JUPITER = (1.9e+27,   7.1492e7)
    SATURN  = (5.688e+26, 6.0268e7)
    URANUS  = (8.686e+25, 2.5559e7)
    NEPTUNE = (1.024e+26, 2.4746e7)

    def __init__(self, mass, radius):
        self.mass = mass       # in kilograms
        self.radius = radius   # in meters

    @property
    def surface_gravity(self):
        # universal gravitational constant  (m3 kg-1 s-2)
        G = 6.67300E-11
        return G * self.mass / (self.radius * self.radius)

>>> Planet.EARTH.value
(5.976e+24, 6378140.0)

>>> Planet.EARTH.surface_gravity
9.802652743337129

Suppose I'm doing something like this, and I want to treat the .values—the tuples like (3.303e+23, 2.4397e6)—as unstable implementation details of the Planet API. I don't want my API consumers to ever rely on them. Instead, I want them to use the properties that I explicitly expose myself, like .surface_gravity.

Is there a conventional way to indicate this?

I'm currently just adding a note in the docstring like this:

class Planet(Enum):
    """.value is an implementation detail. Use .surface_gravity instead."""

But that seems too easy to miss.

If it were a normal class, I would just make it ._value instead of .value. But here, .value is added automatically because I subclassed from Enum, and I don't see a way to override that.

答案1

得分: 2

以下是翻译好的内容：

枚举的确切值几乎总是一个实现细节；之所以将其公开，是因为有时候可以访问它是有用的。

有几种方式来减少它的存在：

• 更改该枚举类的 repr()：

    def __repr__(self):
        return '<%s.%s>' % (self.__class__.__name__, self._name_)

• 使用自定义的 __new__ 来使 value 显然是 "错误" 的，以便视为表面重力（或其他）（可能与上面的 __repr__ 结合使用）：

    def __new__(cls, mass, radius):
        member = object.__new__(cls)
        member._value_ = len(cls._member_names_)
        member.mass = mass
        member.radius = radius
        return member

• 您可以与 dataclass 结合使用（它会自动更新 repr）：

    @dataclass
    class PlanetData:
        mass: float
        radius: float

    class Planet(PlanetData, Enum):
        MERCURY = (3.303e+23, 2.4397e6)
        VENUS   = (4.869e+24, 6.0518e6)
        # 等等

    >>> Planet.VENUS
    <Planet.VENUS: mass=4.869e+24, radius=6051800.0>

披露：我是 Python 标准库 Enum、enum34 回溯 和 高级枚举 (aenum) 库的作者。

    def __repr__(self):
        return '<%s.%s>' % (self.__class__.__name__, self._name_)

    def __new__(cls, mass, radius):
        member = object.__new__(cls):
        member._value_ = len(cls._member_names_)
        member.mass = mass
        member.radius = radius
        return member

    @dataclass
    class PlanetData:
        mass: float
        radius: float

    class Planet(PlanetData, Enum):
        MERCURY = (3.303e+23, 2.4397e6)
        VENUS   = (4.869e+24, 6.0518e6)
        # etc

    >>> Planet.VENUS
    <Planet.VENUS: mass=4.869e+24, radius=6051800.0>

答案2

得分: 0

以下是翻译好的部分：

问题之一是您有一个执行两个任务的单一类：

1. 存储物理常数
2. 进行计算

个人而言，我会将计算分离成一个接受来自枚举的行星参数的全局函数：

def surface_gravity(planet: Planet):
    #...与原实现相同，只需使用 `planet` 替代 `self`。

如果您需要进一步的翻译或帮助，请告诉我。

def surface_gravity(planet: Planet):
    #...same implementation except use `planet` instead of `self`.