Python 3.5異步關鍵字

Question

我目前正在調查pulsar的異步HTTP客戶端。

下面的例子是在文檔：

from pulsar.apps import http 

async with http.HttpClient() as session: 
    response1 = await session.get('https://github.com/timeline.json') 
    response2 = await session.get('https://api.github.com/emojis.json') 

但是當我試着執行它時，我得到

async with http.HttpClient() as session: 
     ^SyntaxError: invalid syntax 

它看起來像async關鍵字無法識別。我正在使用Python 3.5。

工作例如：

import asyncio 

from pulsar.apps.http import HttpClient 

async def my_fun(): 
        async with HttpClient() as session: 
         response1 = await session.get('https://github.com/timeline.json') 
         response2 = await session.get('https://api.github.com/emojis.json') 

        print(response1) 
        print(response2) 


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

Answer 1

你只能使用一個async with裏面coroutines，所以你必須要做到這一點

from pulsar.apps.http import HttpClient 
import pulsar 

async def my_fun(): 
    async with HttpClient() as session: 
     response1 = await session.get('https://github.com/timeline.json') 
     response2 = await session.get('https://api.github.com/emojis.json') 
    return response1, response2 

loop = pulsar.get_event_loop() 
res1, res2 = loop.run_until_complete(my_fun()) 
print(res1) 
print(res2) 

脈衝星內部使用ASYNCIO，所以你不必導入它明確地使用它，通過脈衝星使用它

---

作爲一個側面說明，如果升級到python 3.6你可以使用異步列表/設置/等修真

from pulsar.apps.http import HttpClient 
import pulsar 

async def my_fun(): 
    async with HttpClient() as session: 
     urls=['https://github.com/timeline.json','https://api.github.com/emojis.json'] 
     return [ await session.get(url) for url in urls] 

loop = pulsar.get_event_loop() 
res1, res2 = loop.run_until_complete(my_fun()) 
print(res1) 
print(res2)