How to capture the stream of conversation in a self created network socket using python

For testing purposes I need to create reproducible and deterministic network conversation streams for various application-level protocols using Python. Is there a way to programatically create both client and server parts of a network protocol (like ssh, tls, ftp, etc.) and make them have a simple controllable conversation according to that protocol, while capturing the actual network stream for both sides? What are your suggestions for automatically creating deterministic data streams to be used in test cases for various network protocol parsers?