a = np.random.randn(5)
print(f"{a}n{a.T}")
a = np.random.randn(5,1)
print(f"{a}n{a.T}")
结果有区别！选择第二种，指定矩阵or向量的形式，否则易出现不可预知的错误
[ 0.01961264 -0.85247497 1.23516864 0.88531536 -0.56894737]
[ 0.01961264 -0.85247497 1.23516864 0.88531536 -0.56894737]
[[-0.61408454]
[ 1.65375216]
[-0.48033064]
[-0.40352302]
[ 1.45104431]]
[[-0.61408454 1.65375216 -0.48033064 -0.40352302 1.45104431]]
