def _secondary_values(self):
        """Getter for secondary series values (flattened)"""
        return [
            val for serie in self.secondary_series for val in serie.values
            if val is not None
        ]
def _secondary_values ( self ) : return [ val for serie in self . secondary_series for val in serie . values if val is not None ]
Getter for secondary series values (flattened)