code: def connection_url(self, name=None):
          
          return 'postgresql://{user}@{host}:{port}/{dbname}'.format(**{k: v for k, v in self._connect_options(name)})
docs: Provides a connection string for database as a sqlalchemy compatible URL.
  
          NB - this doesn't include special arguments related to SSL connectivity (which are outside the scope
          of the connection URL format).
  
          Parameters
          ----------
          name: str, optional
              an override database name for the connection string.
  
          Returns
          -------
          str: the connection URL (e.g. postgresql://user1@localhost:5432/db1)