python随机生成两个3*4的整数矩阵，计算两个矩阵的和，最终分别输出三个矩阵。

以下是Python代码实现：

import random

# 随机生成两个3*4的整数矩阵
matrix1 = [[random.randint(1, 10) for j in range(4)] for i in range(3)]
matrix2 = [[random.randint(1, 10) for j in range(4)] for i in range(3)]

# 计算两个矩阵的和
matrix_sum = [[matrix1[i][j] + matrix2[i][j] for j in range(4)] for i in range(3)]

# 分别输出三个矩阵
print("矩阵1：")
for i in range(3):
    print(matrix1[i])

print("矩阵2：")
for i in range(3):
    print(matrix2[i])

print("矩阵1和矩阵2的和：")
for i in range(3):
    print(matrix_sum[i])

运行结果示例：

矩阵1：
[8, 4, 3, 2]
[10, 7, 10, 4]
[1, 9, 9, 2]
矩阵2：
[10, 6, 8, 1]
[7, 9, 5, 8]
[5, 10, 1, 7]
矩阵1和矩阵2的和：
[18, 10, 11, 3]
[17, 16, 15, 12]
[6, 19, 10, 9]