def layout(self, layout):
        """
        Parameters
        ==========
        layout :
            a string with matching the name of a Layout object.
        """
        for index, obj in enumerate(self.layouts):
            if obj.name == layout:
                self.use_layout(index)
                return
        logger.error("No such layout: %s", layout)

        Parameters
        ==========
        layout :
            a string with matching the name of a Layout object.
        
libqtile/group.py