requests_client_cert.py

import requests
from requests.adapters import HTTPAdapter
from requests.packages.urllib3.util.ssl_ import create_urllib3_context

# https://gist.github.com/mtigas/952344
# https://github.com/requests/requests/issues/2118
# https://github.com/requests/requests/issues/3774#issuecomment-267871876

class ClientCertificateAdapter(HTTPAdapter):
    def init_poolmanager(self, *args, **kwargs):
        context = create_urllib3_context()
        context.load_cert_chain(certfile="client.crt", keyfile="client.key", password="cureatr")
        kwargs['ssl_context'] = context
        return super(ClientCertificateAdapter, self).init_poolmanager(*args, **kwargs)

s = requests.Session()
s.mount('https://server.cryptomix.com/secure/', ClientCertificateAdapter())

r = s.get('https://server.cryptomix.com/secure/')
print r.text