Convert a three-dimensional array into a two-dimensional array in numpy

Original link: https://www.cnblogs.com/zz22--/p/7647836.html

The reshape() function in umpy converts a three-dimensional array into a two-dimensional array, see the following example:

>>>a=np.reshape(np.arange(18),(3,3,2))
>>> a
array([[[ 0,  1],
        [ 2,  3],
        [ 4,  5]],

       [[ 6,  7],
        [ 8,  9],
        [10, 11]],

       [[12, 13],
        [14, 15],
        [16, 17]]])
>>>a=reshape(a,(-1,3))
>>>a
array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11],
       [12, 13, 14],
       [15, 16, 17]])

>>>a=np.reshape(np.arange(18),(2,3,3))
>>>a
array([[[ 0,  1,  2],
        [ 3,  4,  5],
        [ 6,  7,  8]],

       [[ 9, 10, 11],
        [12, 13, 14],
        [15, 16, 17]]])
>>>a=np.reshape(a,(-1,3))
>>>array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [ 9, 10, 11],
       [12, 13, 14],
       [15, 16, 17]])