Python类型提示：自定义数据类型

发布于 2025-01-23 14:22:43 字数 567 浏览 0 评论 0 原文

假设，我想拥有一个我称为 size 的自定义类型。从根本上讲，这种类型不过是INT。

但是，我想具有以下行为：

some_size: Size = 42
not_a_size: int = 12

>>> isinstance(some_size, int)
True

>>> isinstance(some_size, Size)
True

>>> isinstance(not_a_size, int)
True

>>> isinstance(not_a_size, Size)
False

定义类型别名： size = int 是可能的，但是 isInstance（not_a_size，size，size）会返回true 。我还探索了 typevar （ size = typevar（'size'，bound = int）），但不是为此做出的。

原文

Let say, I want to have a custom type that I call Size.
Fundamentally, this type is nothing more than an int.

However, I would like to have the following behaviour:

some_size: Size = 42
not_a_size: int = 12

>>> isinstance(some_size, int)
True

>>> isinstance(some_size, Size)
True

>>> isinstance(not_a_size, int)
True

>>> isinstance(not_a_size, Size)
False

Defining a type alias: Size = int is possible, but isinstance(not_a_size, Size) would return True.
I also explored TypeVar (Size = TypeVar('Size', bound=int)) but it is not made for this.