python3矩阵相关问题

我该怎么判断一个矩阵的一行是不是全是0？我想把矩阵中不是0的行全部删除，求答

### 矩阵的乘法
def transpose(x):  ## 求x的转置矩阵
    return list(zip(*x))

def matrixMult(a,b):
    def f(r,c):  ## 求向量 r c 的点积
        return sum([ i*j for i,j in zip(r,c)])
    return [[ f(r,c) for c in transpose(b)] for r in a]

def readMatrix():
    r = []
    while True:
        s = input().strip()
        if s == '': break
        ii = [int(x) for x in s.split(' ') if x != '']
        r.append(ii)
    return r

if __name__ == '__main__':
    a = readMatrix()
    b = readMatrix()
    print(matrixMult(a,b))