Try this if you wan't to use SSL certificates:
import subprocess
try:
# Set scp and ssh data.
connUser = 'john'
connHost = 'my.host.com'
connPath = '/home/john/'
connPrivateKey = '/home/user/myKey.pem'
# Use scp to send file from local to host.
scp = subprocess.Popen(['scp', '-i', connPrivateKey, 'myFile.txt', '{}@{}:{}'.format(connUser, connHost, connPath)])
except CalledProcessError:
print('ERROR: Connection to host failed!')