Python实现矩阵加法和乘法的方法分析

def add(a, b):
   rows = len(a[0])
   cols = len(a)
   c = []
   for i in range(rows):
     temp = []
     for j in range(cols):
       temp.append(a[i][j] + b[i][j])
     c.append(temp)
   return c

def madd(M1, M2):
  if isinstance(M1, (tuple, list)) and isinstance(M2, (tuple, list)):
    return [[m+n for m,n in zip(i,j)] for i, j in zip(M1,M2)]

def multi(M1, M2):
  if isinstance(M1, (float, int)) and isinstance(M2, (tuple, list)):
    return [[M1*i for i in j] for j in M2]
  if isinstance(M1, (tuple, list)) and isinstance(M2, (tuple, list)):
    return [[sum(map(lambda x: x[0]*x[1], zip(i,j)))
         for j in zip(*M2)] for i in M1]