【原】aiohttp 异步http请求-2.post 请求application/json和data

前言

aiohttp 发送post请求，body类型的常见的类型传参：

• application/json

• application/x-www-form-urlencode

application/json

POST 请求接口报文示例，Content-Type类型是application/json

POST /api/v1/login/ HTTP/1.1
Accept: application/json, */*
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Length: 42
Content-Type: application/json
Host: 127.0.0.1:8000
User-Agent: HTTPie/1.0.3

{
    "password": "123456",
    "username": "test"
}

于是可以使用ClientSession.post()接受 json参数

import aiohttp
import asyncio

async def main():
    async with aiohttp.ClientSession('http://127.0.0.1:8000') as session:
        body = {
                    "password": "123456",
                    "username": "test"
                }
        async with session.post('/api/v1/login', json=body) as resp:
            print(resp.url)
            print(await resp.text())

loop = asyncio.get_event_loop()
loop.run_until_complete(main())

运行结果

http://127.0.0.1:8000/api/v1/login
{"code": 0, "msg": "login success!", "username": "test", "token": "ff7b608ed22407a4cd4d2f7beb1bfe9015574bdc"}

默认情况下，会话使用 python 的标准json模块进行序列化。但可以使用不同的 serializer.
ClientSession接受json_serialize 参数：

import ujson

async with aiohttp.ClientSession(
        json_serialize=ujson.dumps) as session:
    await session.post(url, json={'test': 'object'})

笔记：ujson 比json快，但有些不兼容

JSON 响应内容

有一个内置的 JSON 解码器，以防您处理 JSON 数据：

        async with session.post('/api/v1/login', json=body) as resp:
            print(await resp.json())

如果json解码失败，会抛出异常ContentTypeError

    raise ContentTypeError(
aiohttp.client_exceptions.ContentTypeError: 0, message='Attempt to decode JSON with unexpected mimetype: text/html; charset=utf-8'

使用.json()解码器后，会将返回的内容解析成python里面的dict类型，方便取值

        async with session.post('/api/v1/login', json=body) as resp:
            res = await resp.json()
            token = res['token']
            print('token: ', token)

application/x-www-form-urlencode

POST 请求接口报文示例，Content-Type类型是application/x-www-form-urlencode

POST /api/v4/login HTTP/1.1
Content-Length: 29
Content-Type: application/x-www-form-urlencoded

username=test&password=123456

html上form表单数据的提交，只需传一个data参数即可

import aiohttp
import asyncio

async def main():
    async with aiohttp.ClientSession('http://127.0.0.1:8000') as session:
        body = {
                    "password": "123456",
                    "username": "test"
                }
        async with session.post('/api/v4/login', data=body) as resp:
            print(await resp.json())


loop = asyncio.get_event_loop()
loop.run_until_complete(main())

运行结果

{'code': 0, 'msg': 'login success!', 'username': 'test', 'token': '408434b72328ea6740f7f2c260a1c3f97be82fab'}

总结

如果要发送未进行表单编码的数据，可以通过传递 bytes 默认情况下内容类型设置为 'application/octet-stream’：

async with session.post(url, data=b'\x00Binary-data\x00') as resp:
    ...

如果要发送 JSON 数据：

async with session.post(url, json={'example': 'test'}) as resp:
    ...

要发送具有适当内容类型的文本，只需使用data参数

async with session.post(url, data='Тест') as resp:
    ...