The virtuoso.alchemy module defines a SQLAlchemy dialect for Virtuoso. Note that this is in the very early stages of development and the more elaborate things that are possible with SQLAlchemy may not work.
With this package installed and the requisite ODBC drivers configured, you can create a SQLAlchemy engine by doing something like the following:
from sqlalchemy.engine import create_engine
engine = create_engine("virtuoso://dba:dba@VOS")