example-code-2e/17-futures/countries/flags2_threadpool.py
2015-04-17 21:29:30 -03:00

69 lines
2.0 KiB
Python

"""Download flags of countries (with error handling).
ThreadPool version
Sample run::
$ python3 flags2_threadpool.py -s ERROR -e
ERROR site: http://localhost:8003/flags
Searching for 676 flags: from AA to ZZ
30 concurrent connections will be used.
--------------------
150 flags downloaded.
361 not found.
165 errors.
Elapsed time: 7.46s
"""
# BEGIN FLAGS2_THREADPOOL
import collections
from concurrent import futures
import requests
import tqdm # <1>
from flags2_common import main, HTTPStatus # <2>
from flags2_sequential import download_one # <3>
DEFAULT_CONCUR_REQ = 30 # <4>
MAX_CONCUR_REQ = 1000 # <5>
def download_many(cc_list, base_url, verbose, concur_req):
counter = collections.Counter()
with futures.ThreadPoolExecutor(max_workers=concur_req) as executor: # <6>
to_do_map = {} # <7>
for cc in sorted(cc_list): # <8>
future = executor.submit(download_one,
cc, base_url, verbose) # <9>
to_do_map[future] = cc # <10>
done_iter = futures.as_completed(to_do_map) # <11>
if not verbose:
done_iter = tqdm.tqdm(done_iter, total=len(cc_list)) # <12>
for future in done_iter: # <13>
try:
res = future.result() # <14>
except requests.exceptions.HTTPError as exc: # <15>
error_msg = 'HTTP {res.status_code} - {res.reason}'
error_msg = error_msg.format(res=exc.response)
except requests.exceptions.ConnectionError as exc:
error_msg = 'Connection error'
else:
error_msg = ''
status = res.status
if error_msg:
status = HTTPStatus.error
counter[status] += 1
if verbose and error_msg:
cc = to_do_map[future] # <16>
print('*** Error for {}: {}'.format(cc, error_msg))
return counter
if __name__ == '__main__':
main(download_many, DEFAULT_CONCUR_REQ, MAX_CONCUR_REQ)
# END FLAGS2_THREADPOOL