具有用户定义类的类型提示

似乎找不到确切的答案。我想为一个函数做一个类型提示，它的类型是我定义的一些自定义类，称为 CustomClass()。

然后我们假设在一个函数中，称为 FuncA(arg)，我有一个参数叫做 arg。键入提示 FuncA的正确方式是:

def FuncA(arg: CustomClass):

还是说:

from typing import Type


def FuncA(Arg:Type[CustomClass]):

85209

小开

最佳答案

如果 arg接受 CustomClass的实例，则 前者是正确的:

def FuncA(arg: CustomClass):
#     ^ instance of CustomClass

如果你想要 类 CustomClass本身(或子类型)，那么你应该写:

from typing import Type  # you have to import Type


def FuncA(arg: Type[CustomClass]):
#     ^ CustomClass (class object) itself

就像关于打字的文档中写的那样:

class typing.Type(Generic[CT_co])
A variable annotated with C may accept a value of type C. In contrast, a variable annotated with Type[C] may accept values that are classes themselves - specifically, it will accept the class object of C.

The documentation includes an example with the int class:

a = 3         # Has type 'int'
b = int       # Has type 'Type[int]'
c = type(a)   # Also has type 'Type[int]'