code: def todo(self):
          
          if not os.path.exists(self.migrate_dir):
              self.logger.warn('Migration directory: %s does not exist.', self.migrate_dir)
              os.makedirs(self.migrate_dir)
          return sorted(f[:-3] for f in os.listdir(self.migrate_dir) if self.filemask.match(f))
docs: Scan migrations in file system.