如何在Python中使用Dict指定类型提示

Question

我有一个函数将返回一个字典，例如：

from typing import Dict

def foo() -> Dict[]:
    params = {
        "side": "Buy",
        "symbol": "BTCUSDT",
        "order_type": "Market",
        "time_in_force": "PostOnly",
        "reduce_only": False,
        "close_on_trigger": False,
    }
    return {
        "method": "POST",
        "api": "private/linear/order/create",
        "body": params
    }

里面的内容应该是什么Dict[]？

Answer 1

如果你的字典的键都是字符串并且是固定的，那么TypedDictPython3.8+中的 在这里非常合适：

from typing import TypedDict


class Params(TypedDict):
    side: str
    symbol: str
    order_type: str
    time_in_force: str
    reduce_only: bool
    close_on_trigger: bool


class Foo(TypedDict):
    method: str
    api: str
    body: Params


def foo() -> Foo:
    params: Params = {
        "side": "Buy",
        "symbol": "BTCUSDT",
        "order_type": "Market",
        "time_in_force": "PostOnly",
        "reduce_only": False,
        "close_on_trigger": False,
    }
    return {
        "method": "POST",
        "api": "private/linear/order/create",
        "body": params
    }