[::-1] 数组中元素反向

import numpy as np
a = np.arange(8)
print ("生成0-19之间的数组",a)
# 一维数组反向
a1 = a[::-1]
print("将a数组反向",a1)
# 生成0-19之间的数组 [0 1 2 3 4 5 6 7]
# 将a数组反向 [7 6 5 4 3 2 1 0]

# 高维数组则没有反向效果
# 将数组转换为(2,4)
# 将数组转换为(4,2)
a_2_4 = a1.reshape(2, 4)
a_4_2 = a1.reshape(4, 2)
print("将数组转换为(2,4)\n",a_2_4)
print("将数组转换为(4,2)\n",a_4_2)
a_reshape_2_4 = a1.reshape(2, 4)[::-1]
a_reshape_4_2 = a1.reshape(4, 2)[::-1]
print("将(2,4)数组反向\n",a_reshape_2_4)
print("将(4,2)数组反向\n",a_reshape_4_2)
"""将数组转换为(2,4)
 [[7 6 5 4]
 [3 2 1 0]]
将数组转换为(4,2)
 [[7 6]
 [5 4]
 [3 2]
 [1 0]]
将(2,4)数组反向
 [[3 2 1 0]
 [7 6 5 4]]
将(4,2)数组反向
 [[1 0]
 [3 2]
 [5 4]
 [7 6]]"""