new_contents: from sqlalchemy import create_engine
  from sqlalchemy.orm import sessionmaker
  from .models import Base
  from contextlib import contextmanager
  
  
  def get_engine(uri):
      return create_engine(uri)
  
  
  def get_session(engine):
      Session = sessionmaker(bind=engine, expire_on_commit=False)
      Session.scope = lambda: session_scope(Session)
      return Session
  
  
  def create_database(engine):
      Base.metadata.create_all(engine)
  
  
  @contextmanager
  def session_scope(cls):
      """from http://docs.sqlalchemy.org/en/rel_1_0/orm/session_basics.html"""
      session = cls()
      try:
          yield session
          session.commit()
      except:
          session.rollback()
          raise
      finally:
          session.close()
subject: add db support