I'm using aiohttp with limited_as_completed method to speed up scrapping (around 100 million static website pages). However, the code stops after several minutes, and returns the TimeoutError. I tried several things, but still could not prevent the raise asyncio.TimeoutError. May I ask how can I ignore the error, and continue?
The code I'm running is:
N=123
import html
from lxml import etree
import requests
import asyncio
import aiohttp
from aiohttp import ClientSession, TCPConnector
import pandas as pd
import re
import csv
import time
from itertools import islice
import sys
from contextlib import suppress
start = time.time()
data = {}
data['name'] = []
filename = "C:\\Users\\xxxx"+ str(N) + ".csv"
def limited_as_completed(coros, limit):
futures = [
asyncio.ensure_future(c)
for c in islice(coros, 0, limit)
]
async def first_to_finish():
while True:
await asyncio.sleep(0)
for f in futures:
if f.done():
futures.remove(f)
try:
newf = next(coros)
futures.append(
asyncio.ensure_future(newf))
except StopIteration as e:
pass
return f.result()
while len(futures) > 0:
yield first_to_finish()
async def get_info_byid(i, url, session):
async with session.get(url,timeout=20) as resp:
print(url)
with suppress(asyncio.TimeoutError):
r = await resp.text()
name = etree.HTML(r).xpath('//h2[starts-with(text(),"Customer Name")]/text()')
data['name'].append(name)
dataframe = pd.DataFrame(data)
dataframe.to_csv(filename, index=False, sep='|')
limit = 1000
async def print_when_done(tasks):
for res in limited_as_completed(tasks, limit):
await res
url = "http://xxx.{}.html"
loop = asyncio.get_event_loop()
async def main():
connector = TCPConnector(limit=10)
async with ClientSession(connector=connector,headers=headers,raise_for_status=False) as session:
coros = (get_info_byid(i, url.format(i), session) for i in range(N,N+1000000))
await print_when_done(coros)
loop.run_until_complete(main())
loop.close()
print("took", time.time() - start, "seconds.")
The error log is:
Traceback (most recent call last):
File "C:\Users\xxx.py", line 111, in <module>
loop.run_until_complete(main())
File "C:\Users\xx\AppData\Local\Programs\Python\Python37-32\lib\asyncio\base_events.py", line 573, in run_until_complete
return future.result()
File "C:\Users\xxx.py", line 109, in main
await print_when_done(coros)
File "C:\Users\xxx.py", line 98, in print_when_done
await res
File "C:\Users\xxx.py", line 60, in first_to_finish
return f.result()
File "C:\Users\xxx.py", line 65, in get_info_byid
async with session.get(url,timeout=20) as resp:
File "C:\Users\xx\AppData\Local\Programs\Python\Python37-32\lib\site-packages\aiohttp\client.py", line 855, in __aenter__
self._resp = await self._coro
File "C:\Users\xx\AppData\Local\Programs\Python\Python37-32\lib\site-packages\aiohttp\client.py", line 391, in _request
await resp.start(conn)
File "C:\Users\xx\AppData\Local\Programs\Python\Python37-32\lib\site-packages\aiohttp\client_reqrep.py", line 770, in start
self._continue = None
File "C:\Users\xx\AppData\Local\Programs\Python\Python37-32\lib\site-packages\aiohttp\helpers.py", line 673, in __exit__
raise asyncio.TimeoutError from None
concurrent.futures._base.TimeoutError
I have tried 1) add expect asyncio.TimeoutError: pass. Not working
async def get_info_byid(i, url, session):
async with session.get(url,timeout=20) as resp:
print(url)
try:
r = await resp.text()
name = etree.HTML(r).xpath('//h2[starts-with(text(),"Customer Name")]/text()')
data['name'].append(name)
dataframe = pd.DataFrame(data)
dataframe.to_csv(filename, index=False, sep='|')
except asyncio.TimeoutError:
pass
2) suppress(asyncio.TimeoutError)as shown above. Not working
I just learned aiohttp yesterday, so maybe there is other things wrong in my code that causes timeout error only after a few minutes' running? Thank you very much if anyone knows how to deal with it!
Simple example (not very good, but works fine):
import asyncio
from aiohttp.client import ClientSession
class Wrapper:
def __init__(self, session):
self._session = session
async def get(self, url):
try:
async with self._session.get(url, timeout=20) as resp:
return await resp.text()
except Exception as e:
print(e)
loop = asyncio.get_event_loop()
wrapper = Wrapper(ClientSession())
responses = loop.run_until_complete(
asyncio.gather(
wrapper.get('http://google.com'),
wrapper.get('http://google.com'),
wrapper.get('http://google.com'),
wrapper.get('http://google.com'),
wrapper.get('http://google.com')
)
)
print(responses)