code: def fix_2to3(source,
               aggressive=True, select=None, ignore=None, filename=''):
      
      if not aggressive:
          return source
  
      select = select or []
      ignore = ignore or []
  
      return refactor(source,
                      code_to_2to3(select=select,
                                   ignore=ignore),
                      filename=filename)
docs: Fix various deprecated code (via lib2to3).