Mypy：使用高级（个人）类型

Question

我最近发现了mypy，我想用它检查代码的类型。你知道吗

我有一个Something基类：

class Something():
    ... something...

我有几个子类，它们都是Something的实例，但类型不同：

class Thing(Something)
    def __init__():
        short_name = "S"


class OtherThing(Something)
    def __init__():
        short_name = "T"

当我使用这些对象时，我通常会将它们放在一个列表中：

s1 = Thing()
s2 = OtherThing()
list_things: List[Something] = list()
list_things.append(s1)
list_things.append(s2)

但显然我做不到，mypy不承认事物和其他事物是“低级类型”的东西。你知道吗

我该怎么纠正呢？你知道吗

Answer 1

检查Github issue

如图所示，它是按设计的

作为解决方法，引用JukkaL's comment on github：

You can often use Sequence[x] instead of List[x] to get code like your example working. This works because Sequence is covariant and doesn't let you set items in the list, unlike List[x] which is invariant and allows the mutation of the list.