def find_backward_paths(self, start_dataframe_name, goal_dataframe_name):
        """
        Generator which yields all backward paths between a start and goal
        dataframe. Does not include paths which contain cycles.

        Args:
            start_dataframe_name (str) : Name of dataframe to start the search from.
            goal_dataframe_name  (str) : Name of dataframe to find backward path to.

        See Also:
            :func:`BaseEntitySet.find_forward_paths`
        """
        for path in self.find_forward_paths(goal_dataframe_name, start_dataframe_name):
            # Reverse path
            yield path[::-1]

        Generator which yields all backward paths between a start and goal
        dataframe. Does not include paths which contain cycles.

        Args:
            start_dataframe_name (str) : Name of dataframe to start the search from.
            goal_dataframe_name  (str) : Name of dataframe to find backward path to.

        See Also:
            :func:`BaseEntitySet.find_forward_paths`
        
featuretools/entityset/entityset.py