Module-level Singletons

All modules are Singletons by default because of Python's importing behavior. Python works in the following way:

1. Checks whether a Python module has been imported.
2. If imported, returns the object for the module. If not imported, imports and instantiates it.
3. So when a module gets imported, it is initialized. However, when the same module is imported again, it's not initialized again, which relates to the Singleton behavior of having only one object and returning the same object.