code: def revision(directory=None, message=None, autogenerate=False, sql=False,
               head='head', splice=False, branch_label=None, version_path=None,
               rev_id=None):
      
      config = current_app.extensions['migrate'].migrate.get_config(directory)
      if alembic_version >= (0, 7, 0):
          command.revision(config, message, autogenerate=autogenerate, sql=sql,
                           head=head, splice=splice, branch_label=branch_label,
                           version_path=version_path, rev_id=rev_id)
      else:
          command.revision(config, message, autogenerate=autogenerate, sql=sql)
docs: Create a new revision file.