Python Wordpress-XMLRPC: ServerConnectionError: <ProtocolError 409 Conflict>
Not sure how useful this will be (especially after so long), but in my case, the "409 Conflict" seems to be tied to Modsecurity issues on the hosting provider side (Bluehost), which were triggered by the code accessing the server on a regular basis. So it might be a case of needing to talk to your hosting provider, if that is applicable (e.g. if you're not locally hosting).