FastAPI--响应报文(4)

一、概述

使用response_model定义

请求一个接口返回来我们客户端可见的东西都是所谓的响应报文，如响应头，响应码，响应内容等。

通常不会那么傻的用户输入什么就返回什么。以下的官网示例纯粹的演示看：

import uvicorn

from fastapi import FastAPI
from pydantic import BaseModel, EmailStr

app = FastAPI()

class UserIn(BaseModel):
    username: str
    password: str
    email: str
    full_name: str = None

class UserOut(BaseModel):
    username: str
    email: str
    full_name: str = None

@app.post("/user/", response_model=UserOut)
async def create_user(*, user: UserIn):
    return user

if __name__ == '__main__':
    uvicorn.run(app='main:app', host="127.0.0.1", port=8000, reload=True, debug=True)

json参数

{
    "username":"xiao",
    "password":"1234",
    "email":"12345678@qq.com",
    "full_name":"肖"
}

通常再定义我们的API返回响应的时候，一般是返回固定JSON格式的，所以可以直接使用定义response_model为一个字典：

import uvicorn

from fastapi import FastAPI
from typing import Dict

app = FastAPI()

@app.get("/keyword-weights/", response_model=Dict[str, float])
async def read_keyword_weights():
    return {"foo": 2.3, "bar": 3.4}

if __name__ == '__main__':
    uvicorn.run(app='main:app', host="127.0.0.1", port=8000, reload=True, debug=True)

json参数

{
    "username":"xiao",
    "password":"1234",
    "email":"12345678@qq.com",
    "full_name":"肖"
}

关于响应状态码status_code

通常的一个接口请求完成，如果没有什么异常通常会返回200：如日志打印出来一样：

INFO:     127.0.0.1:58141 - "POST /user/ HTTP/1.1" 400
INFO:     127.0.0.1:58315 - "POST /user/ HTTP/1.1" 200

FastAPI运行我们的指定返回的status_code，如下示例：

import uvicorn

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()

class UserIn(BaseModel):
    username: str
    password: str
    email: str
    full_name: str = None

class UserOut(BaseModel):
    username: str
    email: str
    full_name: str = None

@app.post("/user/", response_model=UserOut,status_code=500)
async def create_user(*, user: UserIn):
    return user

if __name__ == '__main__':
    uvicorn.run(app='main:app', host="127.0.0.1", port=8000, reload=True, debug=True)

由于在路由中定死了状态码500，所以这里就是500

甚至还可以通过导入status来指定：

import uvicorn
from fastapi import FastAPI, status

app = FastAPI()

@app.post("/items/", status_code=status.HTTP_201_CREATED)
async def create_item(name: str):
    return {"name": name}

if __name__ == '__main__':
    uvicorn.run(app='main:app', host="127.0.0.1", port=8000, reload=True, debug=True)