Always aplying a bit of unit testing with huge steps, but gradually finding the result. For example, if Queue is created using a Stack that is using a Linked list, I started by creating and testing the linked list, then the Stack and finally the Queue.

Not packaging yet, so simple export path will do for the tests: export PYTHONPATH="${PYTHONPATH}:YOUR_ABSOLUTE_PATH_TO_THE_PROJECT_FOLDER"

In my case I did this in a virtual env: export PYTHONPATH="${PYTHONPATH}:/Users/david/__PYTHON/DataStructures/datastructures"