python - requests, cannot assign requested address, out of ports? -

requests.exceptions.connectionerror: ('connection aborted.', error(99, 'cannot assign requested address')) 

i getting error when running multiple processes utilizing python requests library , calling post function api returning (<10ms).

dialing down number of processes running had delaying effect, dialing down 1 process eliminated problem. not solution, did indicate finite resource culprit.

the way resolved issue use requests.session class reuse same connection/session each call in given process.

contrived example:

import requests line in file:   requests.get('http://example.com/api?key={key}'.format(key=line['key'])) 

becomes

import requests requests.session() session:   line in file:     session.get('http://example.com/api?key={key}'.format(key=line['key'])) 

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repeated post request causing error "socket.error: (99, 'cannot assign requested address')" python urllib2: cannot assign requested address