scalar expected, use tensorproduct(...) for tensorial product

Raise code

    def __mul__(self, other):
        from sympy.matrices.matrices import MatrixBase
        from sympy.tensor.array import SparseNDimArray
        from sympy.tensor.array.arrayop import Flatten

        if isinstance(other, (Iterable, NDimArray, MatrixBase)):
            raise ValueError("scalar expected, use tensorproduct(...) for tensorial product")

        other = sympify(other)
        if isinstance(self, SparseNDimArray):
            if other.is_zero:
                return type(self)({}, self.shape)
            return type(self)({k: other*v for (k, v) in self._sparse_array.items()}, self.shape)