httpx可以替代requests,它可以用来发送同步以及异步请求

使用方式基本和requests类似：

如：res=httpx.get('htttp://www.baidu.com')
assert res.status_code==200

*在公司遇到问题，因为公司网络使用了代理，这样写时，会报407错误
因此要把proxy加上
proxys={"http://":None}
不需要使用代理的时候
res=httpx.get('htttp://www.baidu.com',proxys=proxy)
assert res.status_code==200

异步请求：

import httpx
import asyncio
async def get_content(link):
    async with httpx.AsyncClient() as client: #类似于requests的session
  
        headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) '
                          'Chrome/94.0.4606.81 Safari/537.36'}
            #await client.get(login)
            res = await client.get(link)
            print(res.text)
links=['http://www.baidu.com','http://www.sina.com'] 
tasks=[]
    for name, link in linklist:
        task.append(get_content(link))

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

如果是非主线程调用
loop=asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop.run_until_complete(tasks)

python3.7最新写法

import asyncio

 
 async def main():
     tasks = []
    #设置link列表
     for i in links
         tasks.append(asyncio.create_task(get_content(i)))
         
     await asyncio.wait(tasks)
    
 if __name__ == '__main__':
     asyncio.run(main())

使用gather

async def main():
     tasks = []
       #设置link列表
     for i in links
         tasks.append(get_content(i))      
     await asyncio.gather(*tasks)

*获取wait的执行结果

 async def main():
     tasks = []
     for i in links:
         tasks.append(asyncio.create_task(get_content(i)))
         
     # 获取任务执行结果。
     done, pending = await asyncio.wait(tasks)
   
    #done, pending = await asyncio.wait(tasks, timeout=10) 设置超时时间
     for task in done:
         print(f"执行结果: {task.result()}")
 
 if __name__ == '__main__':
     asyncio.run(main())

*使用gather获取协程执行结果

import httpx
import asyncio
async def get_content(link):
    async with httpx.AsyncClient() as client: #类似于requests的session
  
        headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) '
                          'Chrome/94.0.4606.81 Safari/537.36'}
            #await client.get(login)
            res = await client.get(link)
            return res.status_code

async def main():
     tasks = []
     for i in links:
         tasks.append(get_content(i))
 
     results = await asyncio.gather(*tasks)
     for result in results:
         print(f"执行结果: {result}")  #返回所有任务执行结果

*直接使用回调函数获取结果

• 回调函数

 def callback(task):
     print(f"执行结果:{task.result()}")

async def main():
     tasks = []
     for i in links:
         task = asyncio.create_task(get_content(i))

         # 注意这里，增加回调函数
         task.add_done_callback(callback)
         tasks.append(task)

参考：https://mp.weixin.qq.com/s?__biz=MjM5OTMyODA4Nw%3D%3D&chksm=a73c69e1904be0f72563bc478daf04a4f4277e60756032ff2166195cac21202ccec60a64d911&idx=1&mid=2247485913&scene=21&sn=f5392cd77d202082928325ca0e6f07c8#wechat_redirect