numpy.concatenate((a1, a2, ...), axis=0) Join a sequence of arrays along an existing axis.(按轴axis连接array组成一个新的array) The arrays must have the same shape, except in the dimension corresponding to axis axis:default is 0 >>> a = np.array([[1, 2], [3
Implement an iterator to flatten a 2d vector. For example,Given 2d vector = [ [1,2], [3], [4,5,6] ] By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1,2,3,4,5,6]. Hint: How many variables do y