Sqlalchemy sqlite url relative to home or environment variable

A relative sqlalchemy path to a sqlite database can be written as:


And an absolute one as:


Is it possible to write a path relative to home? Like this:


Or even better, can the path contain environment variables?


This is the context of an alembic.ini file. So if the previous objectives are not possible directly, may I be able to cheat using variable substitution?

script_location = db_versions
sqlalchemy.url = sqlite:///%(MY_FOLDER)s.db