Fastapi 请求参数和验证

请求参数和认证　　

枚举类型的参数

from datetime import date
from enum import Enum
from typing import Optional, List

from fastapi import APIRouter, Query, Path, Body, Cookie, Header
from pydantic import BaseModel, Field

app03 = APIRouter()


class CityName(str, Enum):
    Beijing = "Beijing China"
    Shanghai = "Shanghai China"


@app03.get("/enum/{city}")  
async def latest(city: CityName):
    if city == CityName.Shanghai:
        return {"city_name": city, "confirmed": 1492, "death": 7}
    if city == CityName.Beijing:
        return {"city_name": city, "confirmed": 971, "death": 9}
    return {"city_name": city, "latest": "unknown"}

　路径参数和数字认证

from fastapi import Path

@app03.get("/path_/{num}")
def path_params_validate(
    num: int = Path(..., title="Your Number", description="不可描述", ge=1, le=10),
):
    return num

Path

• ... 表示该参数是必需的

• title="Your Number" 表示参数的标题为 "Your Number"

• description="不可描述" 表示参数的描述为 "不可描述"

• ge=1 表示参数的值必须大于等于 1

• le=10 表示参数的值必须小于等于 10

通过path parameters传递文件路径

@app03.get("/files/{file_path:path}")
def filepath(file_path: str):
    return f"The file path is {file_path}"

查询参数和字符串验证

给了默认值就是选填的参数，没给默认值就是必填参数

@app03.get("/query")
def page_limit(page: int = 1, limit: Optional[int] = None):  
    if limit:
        return {"page": page, "limit": limit}
    return {"page": page}

bool类型转换：yes on 1 True true会转换成true, 其它为false

@app03.get("/query/bool/conversion")
def type_conversion(param: bool = False):
    return param

长度+正则表达式验证，比如长度8-16位，以a开头。其它校验方法看Query类的源码

@app03.get("/query/validations")  
def query_params_validate(
    value: str = Query(..., min_length=8, max_length=16, regex="^a"),  # ...换成None就变成选填的参数
    values: List[str] = Query(["v1", "v2"], alias="alias_name")
):  # 多个查询参数的列表。参数别名
    return value, values

请求体和字段

example是注解的作用，值不会被验证

class CityInfo(BaseModel):
    name: str = Field(..., example="Beijing")
    country: str
    country_code: str = None  # 给一个默认值
    country_population: int = Field(default=800, title="人口数量", description="国家的人口数量", ge=800)

    class Config:
        schema_extra = {
            "example": {
                "name": "Shanghai",
                "country": "China",
                "country_code": "CN",
                "country_population": 1400000000,
            }
        }


@app03.post("/request_body/city")
def city_info(city: CityInfo):
    print(city.name, city.country)  # 当在IDE中输入city.的时候，属性会自动弹出
    return city.dict()

Request Body + Path parameters + Query parameters 多参数混合

@app03.post("/request_body/city")
def city_info(city: CityInfo):
    print(city.name, city.country)  # 当在IDE中输入city.的时候，属性会自动弹出
    return city.dict()


"""Request Body + Path parameters + Query parameters 多参数混合"""


@app03.put("/request_body/multiple/parameters")
def body_multiple_parameters(
    city: CityInfo = Body(..., embed=True),  # 当只有一个Body参数的时候，embed=True表示请求体参数嵌套。多个Body参数默认就是嵌套的
    confirmed: int = Query(ge=0, description="确诊数", default=0),
    death: int = Query(ge=0, description="死亡数", default=0),
):
    print(f"{city.name} 确诊数：{confirmed} 死亡数：{death}")
    return city.dict()

Request Body - Nested Models 数据格式嵌套的请求体

class CityInfo(BaseModel):
    name: str = Field(..., example="Beijing")  # example是注解的作用，值不会被验证
    country: str
    country_code: str = None  # 给一个默认值
    country_population: int = Field(default=800, title="人口数量", description="国家的人口数量", ge=800)

    class Config:
        schema_extra = {
            "example": {
                "name": "Shanghai",
                "country": "China",
                "country_code": "CN",
                "country_population": 1400000000,
            }
        }


class Data(BaseModel):
    city: List[CityInfo] = None  # 这里就是定义数据格式嵌套的请求体
    date: date  # 额外的数据类型，还有uuid datetime bytes frozenset等，参考：https://fastapi.tiangolo.com/tutorial/extra-data-types/
    confirmed: int = Field(ge=0, description="确诊数", default=0)
    deaths: int = Field(ge=0, description="死亡数", default=0)
    recovered: int = Field(ge=0, description="痊愈数", default=0)


@app03.put("/request_body/nested")
def nested_models(data: Data):
    return data

Cookie 和 Header 参数

from fastapi import APIRouter, Query, Path, Body, Cookie, Header

@app03.get("/cookie")  # 效果只能用Postman测试
def cookie(cookie_id: Optional[str] = Cookie(None)):  # 定义Cookie参数需要使用Cookie类，否则就是查询参数
    return {"cookie_id": cookie_id}


@app03.get("/header")
def header(user_agent: Optional[str] = Header(None, convert_underscores=True), x_token: List[str] = Header(None)):
    """
    有些HTTP代理和服务器是不允许在请求头中带有下划线的，所以Header提供convert_underscores属性让设置
    :param user_agent: convert_underscores=True 会把 user_agent 变成 user-agent
    :param x_token: x_token是包含多个值的列表
    :return:
    """
    return {"User-Agent": user_agent, "x_token": x_token}