__用于约束Python中属性创建的setattr\uuuuuuuuuuu与uuuuuuuu插槽

我一直在读关于如何降低Python类的动态性，特别是通过不允许用户动态创建新属性。我读过了，还有。实际上，有人认为，

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

可以打破酸洗。（有人能证实这一点吗？）

然而，我刚刚阅读了Python2.2的whatsnew，实际上建议使用

\uuuuu slots\uuuu

来限制属性创建，而不仅仅是像其他人建议的那样进行优化。就Python的历史而言，有人知道

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

的初衷是什么吗？约束变量的创建是一个被滥用的特性还是一个错误？人们是如何看待实践中使用的

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

？有很多人看到过重载来限制属性创建吗？哪一个最好？如果你更熟悉一种或另一种方法，请随时发布你所知道的方法的优缺点。另外，如果你有不同的解决问题的方法，请分享！（请不要重复已在中表示的

\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

编辑：我希望避免讨论“为什么？”，但第一个答案表明这将出现，所以我将在这里陈述。在所讨论的项目中，我们使用这些类来存储“配置信息”，允许用户使用其（用户）参数设置对象的属性，然后将对象传递给程序的另一部分。这些对象不仅仅是存储参数，所以字典不起作用。我们已经有用户意外地键入了错误的属性名称，并最终创建了一个新属性，而不是设置程序期望的属性之一。这不会被检测到，因此用户认为他们正在设置参数，但看不到预期结果。这让用户感到困惑，而且很难发现。通过约束属性创建，异常将被抛出，而不是静默地传递

编辑2，重新酸洗：这些对象将是我们将来想要存储的东西，酸洗似乎是一种很好的方法。如果
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

编辑3：我还应该提到，内存保护不是一个问题。这些对象很少会被创建，因此任何节省的内存都可以忽略不计（比如3-12GB机器上的10s千字节）。
为什么要限制开发人员这样做？除了“我不想让他们这么做”之外，还有什么技术原因吗？如果没有，就不要这样做

无论如何，使用
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu。但是，如果某些代码需要对象具有
\uuu dict\uuu
，则无法使用它

如果有很好的理由限制它（同样，你确定有吗？）或者你需要节省那一点点内存，请选择
\uuuuu插槽\uuuu


阅读说明后，您可能希望使用
\uuuuu setattr\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu。这样，您可以显示一些更有用的信息，例如哪些类似属性可用。可能的实现如下所示：

class Test(object):
    __slots__ = ('foo', 'bar', 'moo', 'meow', 'foobar')

    def __setattr__(self, name, value):
        try:
            object.__setattr__(self, name, value)
        except AttributeError:
            alts = sorted(self.__slots__, key=lambda x: levenshtein(name, x))
            msg = "object has no attribute '{}', did you mean '{}'?"
            raise AttributeError(msg.format(name, alts[0]))

我使用的
levenshtein（）
是来自的实现4。对于不太聪明的用户，您可能希望使错误更加详细，并包括所有接近的匹配项，而不仅仅是第一个匹配项

您可以通过创建一个仅包含
\uuuu setattr\uuu
方法的mixin类来进一步改进代码。这样，您就可以将代码排除在实际类之外，并且在必要时还可以使用自定义的
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
（只需使用
超级（…）。\uu？除了“我不想让他们这么做”之外，还有什么技术原因吗？如果没有，就不要这样做

无论如何，使用
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu。但是，如果某些代码需要对象具有
\uuu dict\uuu
，则无法使用它

如果有很好的理由限制它（同样，你确定有吗？）或者你需要节省那一点点内存，请选择
\uuuuu插槽\uuuu


阅读说明后，您可能希望使用
\uuuuu setattr\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu。这样，您可以显示一些更有用的信息，例如哪些类似属性可用。可能的实现如下所示：

class Test(object):
    __slots__ = ('foo', 'bar', 'moo', 'meow', 'foobar')

    def __setattr__(self, name, value):
        try:
            object.__setattr__(self, name, value)
        except AttributeError:
            alts = sorted(self.__slots__, key=lambda x: levenshtein(name, x))
            msg = "object has no attribute '{}', did you mean '{}'?"
            raise AttributeError(msg.format(name, alts[0]))

我使用的
levenshtein（）
是来自的实现4。对于不太聪明的用户，您可能希望使错误更加详细，并包括所有接近的匹配项，而不仅仅是第一个匹配项

您可以通过创建一个仅包含
\uuuu setattr\uuu
方法的mixin类来进一步改进代码。这样，您就可以将代码排除在实际类之外，并且在必要时还可以自定义
\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
（只需在mixin中使用
超级（…）。\uuuuuuuuuuuuuuuuu
我对您的用例的建议是使用
\uuuuSetAttr\uuuuuuuuuuuuuu
并在使用Python模块无法识别属性名称时发出警告。
我对您的用例的建议是使用
\uuuuuuSetAttr\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
并在使用Python模块无法识别属性名称时发出警告。
我相信插槽是正确的int