code: async def change_directory(self, path=".."):
          
          path = pathlib.PurePosixPath(path)
          if path == pathlib.PurePosixPath(".."):
              cmd = "CDUP"
          else:
              cmd = "CWD " + str(path)
          await self.command(cmd, "2xx")
docs: :py:func:`asyncio.coroutine`
  
          Change current directory. Goes «up» if no parameters passed.
  
          :param path: new directory, goes «up» if omitted
          :type path: :py:class:`str` or :py:class:`pathlib.PurePosixPath`