https://github.com/kennethreitz/requests/issues/500

requests-issue-500.py

import sys
from requests import request
from requests import async

URL = 'http://httpbin.org/get'

def get():
    return request('get', URL)
    
def async_get():
    req = async.request('get', URL)
    return async.map([req])[0]

if __name__ == '__main__':
    all = 50

    for get, mode in ((get, 'SYNC'), (async_get, 'ASYNC')):
        failed = 0
        exceptions = 0
        for run in xrange(all):
            try:
                res = get()
                if res:
                    print '.',            
                else:
                    print '*',
                    failed += 1
            except Exception:
                print 'x',
                exceptions +=1
        print '\n%s http errors: %f%%, exceptions %f%%' % (mode,
                                                           (float(failed)/all)*100,
                                                           (float(exceptions)/all)*100)