例1:将数组旋转90度
1 a = [[i for i in range(4)] for n in range(4)]
2 print(a)
3 # 遍历大序列
4 for a_index, w in enumerate(a): # enumaerate()遍历数据对象,同时列出数据和数据下标
5 # 遍历大序列里的小序列
6 for m_index in range(a_index, len(w)): # range(w_index, )使for循环从w_index行开始替换
7 tmp = a[m_index][a_index] # 将大序列里的值存起来
8 a[m_index][a_index] = w[a_index] # 将小序列的值放到大序列
9 a[a_index][m_index] = tmp #将存起来的值放到小序列里
10 print('----------------')
11 for r in a: #查看转换过程
12 print(r)
结果:
[[0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3]]
----------------
[0, 0, 0, 0]
[0, 1, 2, 3]
[0, 1, 2, 3]
[0, 1, 2, 3]
----------------
[0, 0, 0, 0]
[0, 1, 1, 1]
[0, 1, 2, 3]
[0, 1, 2, 3]
----------------
[0, 0, 0, 0]
[0, 1, 1, 1]
[0, 1, 2, 2]
[0, 1, 2, 3]
----------------
[0, 0, 0, 0]
[0, 1, 1, 1]
[0, 1, 2, 2]
[0, 1, 2, 3]
0