Overview

This small changeset should provide backward compatibility with Python 3.7 through the following main changes:

• Revised type union notation (e.g. arg: A | B) to use typing.Union or typing.Optional; this also necessitated the removal of from __future__ import annotations
• Added the typing_extensions dependency for Python 3.7 environments in order to provide support for TypedDict

Once merged, this resolves #13

Testing needed

• All current unit tests should pass
  • Python 3.7
  • Python 3.8+ (still working on it)