hstack() Stack arrays in sequence horizontally (column wise).
dstack() Stack arrays in sequence depth wise (along third dimension).
二、numpy.hstack()函数
函数原型:numpy.hstack(tup)
等价于:np.concatenate(tup, axis=1)
自己的理解: 在最里面的维度叠加
三、numpy.vstack()函数
函数原型:numpy.vstack(tup)
等价于:np.concatenate(tup, axis=0) if tup contains arrays thatare at least 2-dimensional.
自己的理解:在次里面的维度叠加