Python 相当于 typedef

Question

定义（非class）类型的python方法是什么：

typedef Dict[Union[int, str], Set[str]] RecordType

Answer 1

这样就可以了？

from typing import Dict, Union, Set

RecordType = Dict[Union[int, str], Set[str]]


def my_func(rec: RecordType):
    pass


my_func({1: {'2'}})
my_func({1: {2}})

此代码将在您的 IDE 第二次调用 my_func 时生成警告，但不会在第一次调用时生成。正如@sahasrara62 所指出的，这里有更多内容 https://docs.python.org/3/library/stdtypes.html#types-genericalias

Answer 2

如果用户寻找 distinct 标称类型定义：

from typing import Dict, Union, Set, NewType

RecordType = Dict[Union[int, str], Set[str]]
DistinctRecordType = NewType("DistinctRecordType", Dict[Union[int, str], Set[str]])

def foo(rec: RecordType):
    pass

def bar(rec: DistinctRecordType):
    pass

foo({1: {"2"}})
bar(DistinctRecordType({1: {"2"}}))
bar({1: {"2"}}) # <--- this will cause a type error

此代码段演示了只有显式转换才行。

$ mypy main.py
main.py:14: error: Argument 1 to "bar" has incompatible type "Dict[int, Set[str]]"; expected "DistinctRecordType"
Found 1 error in 1 file (checked 1 source file)

Python 相当于 typedef

Python equivalent for typedef

python

user-defined-types