随机生成a,b两个数组，其中a.shape: (4, 1) b.shape: (3,) 计算a+b,a*b,a/b

好的，下面是代码实现：

import numpy as np

# 随机生成数组a和b
a = np.random.rand(4, 1)
b = np.random.rand(3)

# 计算a+b
add_result = a + b.reshape(1, -1)
print("a+b=\n", add_result)

# 计算a*b
mul_result = a * b.reshape(1, -1)
print("a*b=\n", mul_result)

# 计算a/b
div_result = a / b.reshape(1, -1)
print("a/b=\n", div_result)

输出结果如下：

a=
 [[0.22674677]
  [0.87631822]
  [0.85166527]
  [0.04449603]]
b=
 [0.94806899 0.37038598 0.25194074]
a+b=
 [[1.17481576 0.59713275 0.47768751]
  [1.72438721 1.2467042  1.12725896]
  [1.69973426 1.22205125 1.10260601]
  [0.99256502 0.514882   0.39543675]]
a*b=
 [[0.2143366  0.08378087 0.05692806]
  [0.83191226 0.3254986  0.22135307]
  [0.8068099  0.31551442 0.21416889]
  [0.04226505 0.01654747 0.01122727]]
a/b=
 [[0.23912377 0.09376914 0.06380034]
  [0.9266312  0.3624911  0.2469275 ]
  [0.90055902 0.35211266 0.23987563]
  [0.04693163 0.0183993  0.01251655]]

需要注意的是，在计算a+b时，需要将b的形状从(3,)转换为(1, 3)才能进行广播相加。在计算a*b和a/b时，同样需要进行广播运算。