1

使用 Pyright 检查以下代码：

from typing import Union, TypeVar

T = TypeVar('T')
X_or_RecurListOf = Union[T, list['X_or_RecurListOf']]
x: X_or_RecurListOf[str] = ['asd']

产生错误：

  5:28 - error: Expression of type "list[str]" cannot be assigned to declared type "X_or_RecurListOf[str]"
    Type "list[str]" cannot be assigned to type "X_or_RecurListOf[str]"
      "list[str]" is incompatible with "str"
        TypeVar "_T@list" is invariant
          Type "str" cannot be assigned to type "X_or_RecurListOf[Type[T@X_or_RecurListOf]]"
            Type "str" cannot be assigned to type "T@X_or_RecurListOf"
            "str" is incompatible with "list[X_or_RecurListOf]" (reportGeneralTypeIssues)
1 error, 0 warnings, 0 infos 
Completed in 0.677sec

难道我做错了什么？
还是我误解了Pyright 中支持递归类型的公告？

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1 回答 1

0

哦，我找到了 Pyright 绊倒的地方！

它希望在递归定义中有类型参数：
X_or_RecurListOf = Union[T, list['X_or_RecurListOf[T]']]- 注意[T]！

我不明白为什么这是必要的，但它对我有用，尤其是当我真正的意思是X_or_RecurListOf[T]而不是X_or_RecurListOf[Any].

于 2021-03-04T09:10:11.423 回答