This is required because SQLAlchemy will ensure that an object
coming from the database does not change sessions. In the previous
implementation, if an item existed already, we would find it in the
database from update_or_create from which it would bring its session.
We would then try to add it to the session crated in process_item
which would fail.
Since both methods exist in the same module though, they can simply
share a module-global session.
Changing it to this allows us to update entries that already exist
in the database.
This is required because SQLAlchemy will ensure that an object coming from the database does not change sessions. In the previous implementation, if an item existed already, we would find it in the database from
update_or_createfrom which it would bring its session. We would then try to add it to the session crated inprocess_itemwhich would fail. Since both methods exist in the same module though, they can simply share a module-global session. Changing it to this allows us to update entries that already exist in the database.