And the answer is: do not use requests, as it is blocking. Use non-blocking network I/O, for example eventlet:
import eventlet
from eventlet.green import urllib2
from eventlet.timeout import Timeout
url5 = 'http://ipv4.download.thinkbroadband.com/5MB.zip'
url10 = 'http://ipv4.download.thinkbroadband.com/10MB.zip'
urls = [url5, url5, url10, url10, url10, url5, url5]
def fetch(url):
response = bytearray()
with Timeout(60, False):
response = urllib2.urlopen(url).read()
return url, len(response)
pool = eventlet.GreenPool()
for url, length in pool.imap(fetch, urls):
if (not length):
print "%s: timeout!" % (url)
else:
print "%s: %s" % (url, length)
Produces expected results:
http://ipv4.download.thinkbroadband.com/5MB.zip: 5242880
http://ipv4.download.thinkbroadband.com/5MB.zip: 5242880
http://ipv4.download.thinkbroadband.com/10MB.zip: timeout!
http://ipv4.download.thinkbroadband.com/10MB.zip: timeout!
http://ipv4.download.thinkbroadband.com/10MB.zip: timeout!
http://ipv4.download.thinkbroadband.com/5MB.zip: 5242880
http://ipv4.download.thinkbroadband.com/5MB.zip: 5242880