3-路径参数和数字验证

添加路由接口文件

# qpp01/route.py
from fastapi import APIRouter
app03 = APIRouter()

定义路由函数

# 不传参路由
@app03.get("/path/parameters")
def path_params01():
    return {"message": "This is a message"}

# 传参路由 
@app03.get("/path/{parameters}")  # 函数的顺序就是路由的顺序
def path_prams02(parameters: str):
    return {"message": parameters}

注意：

函数的顺序就是路由的顺序，相同的路由优先匹配上面的函数接口

枚举类型参数

from enum import Enum

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


@app03.get("/enum/{city}")  # 枚举类型的参数
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"}

• 使用枚举类可以让文档中，参数变成可选的下拉框
• 不使用不会报错，文档中参数需要填写

通过path parameters传递文件路径

@app03.get("/files/{file_path:path}")  # 通过path parameters传递文件路径
def filepath(file_path: str):
    return f"The file path is {file_path}"

• f模式表示在打括号内可以写python表达式，和react里面的打括号效果一样

路径参数验证

@app03.get("/path_/{num}")
def path_params_validate(
    num: int = Path(default=..., title="Your Number", description="不可描述", ge=1, le=10),
):
    """
    defaylt:默认参数，在路径参数中是必须的，所有一般设置为...
    title:标题
    description：描述
    
    """
    return num

查询参数

@app03.get("/query")
def page_limit(page: int = 1, limit: Optional[int] = None):  # 给了默认值就是选填的参数，没给默认值就是必填参数
    if limit:
        return {"page": page, "limit": limit}
    return {"page": page}

查询参数验证

@app03.get("/query/validations")  # 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
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

表单参数

@app04.post("/login/")
async def login(username: str = Form(...), password: str = Form(...)):  # 定义表单参数
    """用Form类需要pip install python-multipart; Form类的元数据和校验方法类似Body/Query/Path/Cookie"""
    return {"username": username}

布尔类型转换

@app03.get("/query/bool/conversion")  # bool类型转换：yes on 1 True true会转换成true, 其它为false或者报错
def type_conversion(param: bool = False):
    return param

请求体和字段

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,
            }
        }


@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()

多参数混合

@app03.put("/request_body/city/{name}")
def mix_city_info(
    name: str,
    city01: CityInfo,
    city02: CityInfo,  # Body可以是多个的
    confirmed: int = Query(ge=0, description="确诊数", default=0),
    death: int = Query(ge=0, description="死亡数", default=0),
):
    if name == "Shanghai":
        return {"Shanghai": {"confirmed": confirmed, "death": death}}
    return city01.dict(), city02.dict()

数据格式嵌套的请求体

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

总结

• 在使用请求体校验的时候使用Field交要
• 查询参数校验Query
• 路径参数校验Path