There are many methods to communicating between processes. Many methods work best when only using a single programming language, while others require custom packets and parsing.
Simplicity is key and Redis is an efficient solution. Redis is an open-source in-memory database project implementing a distributed, in-memory key-value store.
Package management is hard. Sometimes in Python package development, your local (development) environment may behave a little differently than a deployment target. Below is a simple method I use to replicate a clean environment and test Python package installs and tests.