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"""Compare the speed of downloading URLs sequentially vs. using futures."""
import functools
import time
import timeit
import sys
try:
from urllib2 import urlopen
except ImportError:
from urllib.request import urlopen
from concurrent.futures import (as_completed, ThreadPoolExecutor,
ProcessPoolExecutor)
URLS = ['http://www.google.com/',
'http://www.apple.com/',
'http://www.ibm.com',
'http://www.thisurlprobablydoesnotexist.com',
'http://www.slashdot.org/',
'http://www.python.org/',
'http://www.bing.com/',
'http://www.facebook.com/',
'http://www.yahoo.com/',
'http://www.youtube.com/',
'http://www.blogger.com/']
def load_url(url, timeout):
kwargs = {'timeout': timeout} if sys.version_info >= (2, 6) else {}
return urlopen(url, **kwargs).read()
def download_urls_sequential(urls, timeout=60):
url_to_content = {}
for url in urls:
try:
url_to_content[url] = load_url(url, timeout=timeout)
except:
pass
return url_to_content
def download_urls_with_executor(urls, executor, timeout=60):
try:
url_to_content = {}
future_to_url = dict((executor.submit(load_url, url, timeout), url)
for url in urls)
for future in as_completed(future_to_url):
try:
url_to_content[future_to_url[future]] = future.result()
except:
pass
return url_to_content
finally:
executor.shutdown()
def main():
for name, fn in [('sequential',
functools.partial(download_urls_sequential, URLS)),
('processes',
functools.partial(download_urls_with_executor,
URLS,
ProcessPoolExecutor(10))),
('threads',
functools.partial(download_urls_with_executor,
URLS,
ThreadPoolExecutor(10)))]:
sys.stdout.write('%s: ' % name.ljust(12))
start = time.time()
url_map = fn()
sys.stdout.write('%.2f seconds (%d of %d downloaded)\n' %
(time.time() - start, len(url_map), len(URLS)))
if __name__ == '__main__':
main()
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