Python切片 |在给定大小的组中反转数组

给定一个数组，反转由连续 k 个元素组成的每个子数组。

例子：

Input: 
arr = [1, 2, 3, 4, 5, 6, 7, 8, 9]
k = 3
Output:  
[3, 2, 1, 6, 5, 4, 9, 8, 7]

Input: 
arr = [1, 2, 3, 4, 5, 6, 7, 8]
k = 5
Output:  
[5, 4, 3, 2, 1, 8, 7, 6]

Input: 
arr = [1, 2, 3, 4, 5, 6]
k = 1
Output:  
[1, 2, 3, 4, 5, 6]

Input: 
arr = [1, 2, 3, 4, 5, 6, 7, 8]
k = 10
Output:  
[8, 7, 6, 5, 4, 3, 2, 1]

对于这个问题，我们有现有的解决方案，请参考 Reverse an array in groups of given size 链接。我们可以使用列表切片和 reversed()函数在Python中快速解决这个问题。下面的示例将让您更好地理解方法。

例子：

# function to Reverse an array in groups of given size
  
def reverseGroup(input,k):
  
    # set starting index at 0
    start = 0
  
    # run a while loop len(input)/k times
    # because there will be len(input)/k number 
    # of groups of size k 
    result = []
    while (start

输出：

[5, 4, 3, 2, 1, 8, 7, 6]

使用直接函数

# function to Reverse an array in groups of given size
   
def reverseGroup(a, k):
  
   # take an empty list
   res = []
  
   # iterate over the list with increment of 
   # k times in each iteration
   for i in range(0, len(a), k):
       
       # reverse the list in each iteration over 
       # span of k elements using extend
       res.extend((a[i:i + k])[::-1])
   print(res)
   
# Driver program
if __name__ == "__main__":
    input = [1, 2, 3, 4, 5, 6, 7, 8]
    k = 5
    reverseGroup(input, k)

输出：

[5, 4, 3, 2, 1, 8, 7, 6]