FastAPI/Pydantic中灵活处理字符串到布尔值的智能转换

from typing import Optional
from pydantic import BaseModel

class Misc(BaseModel):
    popup: bool = False
    advertPending: bool = False

from pydantic_core import PydanticCustomError

def str_to_bool(v: str) -> bool:
    """
    将多种字符串表示形式转换为布尔值。
    支持 'true', 'false', 'yes', 'no', 'on', 'off', '1', '0', 'y', 'n', 'enabled', 'disabled'。
    不区分大小写。
    """
    v_lower = v.strip().lower()
    if v_lower in ["y", "yes", "on", "1", "enabled", "true"]:
        return True
    elif v_lower in ["n", "no", "off", "0", "disabled", "false"]:
        return False
    else:
        # 对于无法识别的字符串，抛出自定义Pydantic错误
        raise PydanticCustomError(
            "boolean_parsing",
            "Invalid boolean string: '{value}'. Expected one of 'true', 'false', 'yes', 'no', 'on', 'off', '1', '0', 'y', 'n', 'enabled', 'disabled'.",
            {"value": v}
        )

from typing import Annotated
from pydantic.functional_validators import PlainValidator

# 定义一个扩展的布尔类型，用于处理多种字符串输入
ExtendedBool = Annotated[bool, PlainValidator(str_to_bool)]

from typing import Optional
from pydantic import BaseModel

class Misc(BaseModel):
    # - whether to pop-up checkbox ("true" or "false")
    popup: Optional[ExtendedBool] = None
    # - whether an advertisement is pending to be displayed ("yes" or "no")
    advertPending: Optional[ExtendedBool] = None
    # 也可以直接定义为非可选，并提供默认值
    isEnabled: ExtendedBool = False

from fastapi import FastAPI, Query, HTTPException
from typing import Optional

app = FastAPI()

# 假设 ExtendedBool, str_to_bool, PydanticCustomError 已定义在同一文件或已导入

@app.get("/config")
async def get_configuration(misc: Misc = Depends()):
    """
    获取配置信息，支持多种字符串形式的布尔参数。
    示例请求：
    - /config?popup=true&advertPending=yes
    - /config?popup=1&advertPending=off
    - /config?popup=FALSE&isEnabled=Y
    """
    return {
        "popup_status": misc.popup,
        "advert_pending_status": misc.advertPending,
        "is_enabled_status": misc.isEnabled
    }

# 示例：处理 POST 请求体中的布尔值
@app.post("/update_settings")
async def update_settings(settings: Misc):
    """
    更新设置，请求体中包含多种字符串形式的布尔参数。
    示例请求体：
    {
        "popup": "on",
        "advertPending": "n",
        "isEnabled": "true"
    }
    """
    return {
        "message": "Settings updated successfully",
        "received_popup": settings.popup,
        "received_advert_pending": settings.advertPending,
        "received_is_enabled": settings.isEnabled
    }