python-二维数组实现90度旋转

本篇主要介绍了对一个N*N的数组，如果进行90度的旋转

首先，定义一个一维数组很简单，如下：

a = [i for i in range(10)]
print(a)

-----结果-----
0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

此写法与下面的写法是相同的效果：

a = []
for i in range(10):
    a.append(i)
print(a)

-----结果-----
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

那么二维数组应该如何进行创建呢，如下：

a = [[col for col in range(4)] for row in range(4)]            #创建一个4*4的二维数组
print(a)

-----结果----
[[0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3], [0, 1, 2, 3]]

如果想要直观一些，稍微调整下：

a = [[col for col in range(4)] for row in range(4)]
for i in a:
    print(i)

-----结果-----
[0, 1, 2, 3]
[0, 1, 2, 3]
[0, 1, 2, 3]
[0, 1, 2, 3]

接下来我们就要针对这个数组进行90度的旋转，把

[0, 1, 2, 3]
[0, 1, 2, 3]
[0, 1, 2, 3]
[0, 1, 2, 3]

转换为：

[0, 0, 0, 0]
[1, 1, 1, 1]
[2, 2, 2, 2]
[3, 3, 3, 3]

要实现该功能，我们先把步骤拆为3步：

第一步：

第二步：

第三步：

代码如下：

data = [[col for col in range(4)] for row in range(4)]

for row_index, row in enumerate(data):
    for col_index in range(row_index, len(row)):
        tmp = data[col_index][row_index]                        #设置一个临时变量
        data[col_index][row_index] = row[col_index]
        data[row_index][col_index] = tmp
    print(‘‘)               #防止打印结果看上去混乱，输入一个空内容
    for r in data:          #分步骤打印出转换结果
        print(r)

-----结果-----
[0, 0, 0, 0]
[1, 1, 2, 3]
[2, 1, 2, 3]
[3, 1, 2, 3]

[0, 0, 0, 0]
[1, 1, 1, 1]
[2, 2, 2, 3]
[3, 3, 2, 3]

[0, 0, 0, 0]
[1, 1, 1, 1]
[2, 2, 2, 2]
[3, 3, 3, 3]

[0, 0, 0, 0]
[1, 1, 1, 1]
[2, 2, 2, 2]
[3, 3, 3, 3]