我从here编辑了此代码：import asyncio

import time

from aiohttp import ClientPayloadError

from aiohttp import ClientSession

COUNTER = 1

async def fetch(url, session):

async with session.get(url) as response:

delay = response.headers.get("DELAY")

date = response.headers.get("DATE")

global COUNTER

COUNTER +=1

print("{}. {}:{} with delay {}".format(str(COUNTER), date, response.url, delay))

try:

return await response.text()

except ClientPayloadError:

print("ERROR: ".format(url))

async def bound_fetch(sem, url, session):

# Getter function with semaphore.

async with sem:

await fetch(url, session)

async def run():

urls = [build_url(id) for id in load_ids()]

tasks = []

# create instance of Semaphore

sem = asyncio.Semaphore(1000)

# Create client session that will ensure we dont open new connection

# per each request.

async with ClientSession(conn_timeout=10000, read_timeout=10000) as session:

for url in urls:

#pass Semaphore and session to every GET request

task = asyncio.ensure_future(bound_fetch(sem, url, session))

tasks.append(task)

responses = asyncio.gather(*tasks)

await responses

def build_url(id):

url = 'http://api.metagenomics.anl.gov/annotation/sequence/{}?source=Refseq'.format(id)

return url

def load_ids():

#in the "real" code I will load a file here and extract the ids

return """

mgm4558908.3

mgm4484962.3

mgm4734169.3

mgm4558911.3

mgm4484983.3

mgm4558918.3

""".strip().split()

start = time.clock()

loop = asyncio.get_event_loop()

future = asyncio.ensure_future(run())

loop.run_until_complete(future)

run_time = (start - time.clock())/60

print("this took: {} minutes".format(run_time))

我知道我可以使用：print(await response.text())打印响应数据，但是我不喜欢异步代码，因此我不知道应该如何以及在哪里打开并写入文件。因为我认为在同一时间写入同一个文件时，有某种线程可能会导致问题(我熟悉多处理)。在