矩阵乘积np.dot()

定义：矩阵相乘最重要的方法是一般矩阵乘积。它只有在第一个矩阵的列数（column）和第二个矩阵的行数（row）相同时才有意义  。

公式：

A=[[1,2,3],[4,5,6]]

B=[[1,4],[2,5],[3,6]]

def matxMultiply(A, B):
    newB=list(map(list,zip(*B)))
    A_B=[]
    for i in range(len(A)):
        row = []
        for n in range(len(newB)):
            num=0
            for m in range(len(A[0])):
                num+=A[i][m]*newB[n][m]
            row.append(num)
        A_B.append(row)
    return A_B
if __name__=='__main__':
    A = [[1, 2, 3], [4, 5, 6]]
    B = [[1, 4], [2, 5], [3, 6]]
    print(matxMultiply(A, B))

def matxMultiply(A, B):
    A_B=[]
    for i in range(len(A)):
        row = []
        for n in range(len(B[0])):
            num=0
            for m in range(len(A[0])):
                num+=A[i][m]*B[m][n]
            row.append(num)
        A_B.append(row)
    return A_B
if __name__=='__main__':
    A = [[1, 2, 3], [4, 5, 6]]
    B = [[1, 4], [2, 5], [3, 6]]
    print(matxMultiply(A, B))