Question

我需要编写一个自己乘以矩阵（nXn）的程序。我必须在过程中计算最大值和最小值，而不是最终。

这是我的代码：

import csv
import time

start= time.time()

matrix = [] 

with open('matrix.csv', newline='') as csvfile:
    exc1 = csv.reader(csvfile, delimiter=',', quotechar='|')
    for row in exc1:
        matrix.append(row)

matrix_length=len(matrix)

min = 9999999999999999999999999999999999999999999
max = 0

result = [[None]*matrix_length for _ in range(matrix_length)]

for i in range(matrix_length):
   for j in range(matrix_length):
       for k in range(0,matrix_length):
           result[i][j] += int(matrix[i][k]) * int(matrix[k][j])
       if (int(result[i][j])<min):
               min = int(result[i][j])
       if (int(result[i][j])>max):
               max = int(result[i][j])    

done=time.time()

print("max:",max)
print("min:",min)
print(done-start)

这是错误：

  File "<ipython-input-15-a8472dbf81c8>", line 24, in <module>
    result[i][j] += int(matrix[i][k]) * int(matrix[k][j])

TypeError: unsupported operand type(s) for +=: 'NoneType' and 'int'

你明白这是什么问题吗？

Answer 1

您正在使用None初始化结果矩阵。试试这个：

result = [[0]*matrix_length for _ in range(matrix_length)]

在python（H.W）中单独乘以矩阵

1 个答案: