AttributeError：“模块”对象没有属性“ensure_future”

Posted 2023-02-24

【中文标题】AttributeError：“模块”对象没有属性“ensure_future”

【英文标题】：AttributeError: 'module' object has no attribute 'ensure_future'

【发布时间】：2015-11-02 08:07:56

【问题描述】：

您好，我正在使用 python asyncio 编写一个 n/w 绑定的服务器应用程序，它可以接受一个发布请求。

在发布请求中我接受一个符号参数

请告诉我处理 n/w 绑定应用程序的最佳方法。我在哪里通过向其他 web api 发送发布请求来收集数据。

以下是代码：

import asyncio
import aiohttp
import json
import logging

# async def fetch_content(url, symbols):
# yield from  aiohttp.post(url, symbols=symbols)

@asyncio.coroutine
def fetch_page(writer, url, data):
   response = yield from aiohttp.post(url, data=data)
   resp = yield from response.read_and_close()
   print(resp)
   writer.write(resp) 
   return           


@asyncio.coroutine
def process_payload(writer, data, scale):
   tasks = []
   data = data.split('\r\n\r\n')[1]
   data = data.split('\n')
   data = [x.split(':') for x in data]
   print(data)
   data = x[0]: x[1] for x in data
   print(data)                 
   # data = data[0].split(':')[1]
   data = data['symbols']
   print(data)
   data = data.split(',')
   data_len = len(data)
   data_first = 0
   data_last = scale
   url = 'http://xxxxxx.xxxxxx.xxx/xxxx/xxxx'
   while data_last < data_len:
       tasks.append(asyncio.ensure_future(fetch_page(writer, url,'symbols': ",".join(data[data_first:data_last]))))
       data_first += scale
       data_last += scale 

   tasks.append(asyncio.ensure_future(fetch_page(writer, url,'symbols': ",".join(data[data_first:data_last]))))
   loop.run_until_complete(tasks)    
   return 

@asyncio.coroutine
def process_url(url):
    pass

@asyncio.coroutine
def echo_server():
  yield from asyncio.start_server(handle_connection, 'xxxxxx.xxxx.xxx', 3000)

@asyncio.coroutine
def handle_connection(reader, writer):
   data = yield from reader.read(8192)

   if data:
        message =  data.decode('utf-8')
        print(message)
        yield from process_payload(writer, message, 400)

   writer.write_eof()   
   writer.close()


#url = 'http://XXXXXXX.xxxxx.xxx/xxxx/xxxxxx/xxx'
data = 'symbols': 'GD-US,14174T10,04523Y10,88739910,03209R10,46071F10,77543110,92847N10'

loop = asyncio.get_event_loop()
loop.run_until_complete(echo_server())
try:
    loop.run_forever()
finally:
    loop.close()

但我收到以下错误：

future: <Task finished coro=<handle_connection() done, defined at        fql_server_async_v2.py:53> exception=AttributeError("'module' object has no   attribute 'ensure_future'",)>
Traceback (most recent call last):
File "/home/user/anugupta/lib/python3.4/asyncio/tasks.py", line 234, in _step
result = coro.send(value)
File "fql_server_async_v2.py", line 60, in handle_connection
yield from process_payload(writer, message, 400)
File "/home/user/anugupta/lib/python3.4/asyncio/coroutines.py", line 141, in coro
res = func(*args, **kw)
File "fql_server_async_v2.py", line 41, in process_payload
tasks.append(asyncio.ensure_future(fetch_page(writer, url,  'symbols':",".join(data[data_first:data_last]))))
AttributeError: 'module' object has no attribute 'ensure_future'
^CTraceback (most recent call last):
File "fql_server_async_v2.py", line 72, in <module>
loop.run_forever()
File "/home/user/anugupta/lib/python3.4/asyncio/base_events.py", line 236,  in run_forever
self._run_once()
File "/home/user/anugupta/lib/python3.4/asyncio/base_events.py", line 1017, in _run_once
event_list = self._selector.select(timeout)
File "/home/user/anugupta/lib/python3.4/selectors.py", line 424, in select
fd_event_list = self._epoll.poll(timeout, max_ev)

【问题讨论】：

当我通过对符号参数的发布请求发送大量数据时，无法一次读取全部数据。所以如果批量数据接收到空数据，请告诉我从发布请求中读取批量数据的最佳方法

asyncio.ensure_future 出现在 3.4.4 版本中，我猜你运行的是旧版本。

【参考方案1】：

ensure_future 是在 asyncio 3.4.4 中添加的，对于早期版本，请使用 async。

虽然async 现在已被弃用，但它会在未来得到支持。

【讨论】：

嗨，andrew，你能建议我一些从发布请求中读取批量数据的方法吗？ data = symbols= '56633010,17290810,41308610,05945F10,51384710,74838J10,45168K30' 这里符号包含超过 20000 个值（逗号分隔），这里 data = yield from reader.read(8192) 如果符号给出空数据包含超过 200 个值。请建议我编写批量数据的方法，这些数据是我收到的另一个 Web api 对作者的响应。