example-code-2e/20-executors/getflags/flags2_threadpool.py
2021-10-05 09:52:43 -03:00

75 lines
2.2 KiB
Python
Executable File

#!/usr/bin/env python3
"""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
"""
# tag::FLAGS2_THREADPOOL[]
from collections import Counter
from concurrent.futures import ThreadPoolExecutor, as_completed
import httpx
import tqdm # type: ignore
from flags2_common import main, DownloadStatus
from flags2_sequential import download_one # <1>
DEFAULT_CONCUR_REQ = 30 # <2>
MAX_CONCUR_REQ = 1000 # <3>
def download_many(cc_list: list[str],
base_url: str,
verbose: bool,
concur_req: int) -> Counter[DownloadStatus]:
counter: Counter[DownloadStatus] = Counter()
with ThreadPoolExecutor(max_workers=concur_req) as executor: # <4>
to_do_map = {} # <5>
for cc in sorted(cc_list): # <6>
future = executor.submit(download_one, cc,
base_url, verbose) # <7>
to_do_map[future] = cc # <8>
done_iter = as_completed(to_do_map) # <9>
if not verbose:
done_iter = tqdm.tqdm(done_iter, total=len(cc_list)) # <10>
for future in done_iter: # <11>
try:
status = future.result() # <12>
except httpx.HTTPStatusError as exc: # <13>
error_msg = 'HTTP error {resp.status_code} - {resp.reason_phrase}'
error_msg = error_msg.format(resp=exc.response)
except httpx.RequestError as exc:
error_msg = f'{exc} {type(exc)}'.strip()
except KeyboardInterrupt:
break
else:
error_msg = ''
if error_msg:
status = DownloadStatus.ERROR
counter[status] += 1
if verbose and error_msg:
cc = to_do_map[future] # <14>
print(f'{cc} error: {error_msg}')
return counter
if __name__ == '__main__':
main(download_many, DEFAULT_CONCUR_REQ, MAX_CONCUR_REQ)
# end::FLAGS2_THREADPOOL[]