parameters: (self, fmt)
docstring: Returns a context manager that invokes set_format(fmt) on enter,
          and restores the old format on exit.
docstring_summary: Returns a context manager that invokes set_format(fmt) on enter,
          and restores the old format on exit.
docstring_tokens: Returns a context manager that invokes set_format ( fmt ) on enter and restores the old format on exit .
function: def using_format(self, fmt):
          """
          Returns a context manager that invokes set_format(fmt) on enter,
          and restores the old format on exit.
          """
          old_repr = self._repr
          self.set_format(fmt)
          yield
          self._repr = old_repr
function_tokens: def using_format ( self , fmt ) : old_repr = self . _repr self . set_format ( fmt ) yield self . _repr = old_repr