(self)
return self._cached__len__
Return number of rows in the table. The value is cached so it is
        computed only the first time the length is requested.
Return number of rows in the table. The value is cached so it is
        computed only the first time the length is requested.
Return number of rows in the table . The value is cached so it is computed only the first time the length is requested .
def __len__(self):
        """
        Return number of rows in the table. The value is cached so it is
        computed only the first time the length is requested.
        """
        if self._cached__len__ is None:
            return self._count_rows()
        return self._cached__len__
def __len__ ( self ) : if self . _cached__len__ is None : return self . _count_rows ( ) return self . _cached__len__