Python程序在给定条件下查找列表中的所有组合

给定一个列表，其中一些元素是可选元素的列表。任务是从所有选项中找到所有可能的组合。

例子：

Input : test_list = [“geekforgeeks”, [5, 4, 3], “is”, [“best”, “good”, “better”]], K = 3 
Output : [[‘geekforgeeks’, 5, ‘is’, ‘best’], [‘geekforgeeks’, 4, ‘is’, ‘good’], [‘geekforgeeks’, 3, ‘is’, ‘better’]] 
Explanation : Inner elements picked and paired with similar indices. 5 -> “best”.

Input : test_list = [“geekforgeeks”, [5, 4], “is”, [“best”, “good”]], K = 2 
Output : [[‘geekforgeeks’, 5, ‘is’, ‘best’], [‘geekforgeeks’, 4, ‘is’, ‘good’]] 
Explanation : Inner elements picked and paired with similar indices. 5 -> “best”. 
 

方法：使用循环

在此，我们使用嵌套循环从每个嵌套选项列表中获取索引组合，然后使用外部循环获取所有组合中的默认值。

Python3

# Python3 code to demonstrate working of 
# Optional Elements Combinations
# Using loop
  
# initializing list
test_list = ["geekforgeeks", [5, 4, 3, 4], "is", 
             ["best", "good", "better", "average"]]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing size of inner Optional list 
K = 4
  
res = []
cnt = 0
while cnt <= K - 1:
    temp = []
      
    # inner elements selections
    for idx in test_list:
          
        # checks for type of Elements
        if not isinstance(idx, list):
            temp.append(idx)
        else:
            temp.append(idx[cnt])
    cnt += 1
    res.append(temp)
  
# printing result 
print("All index Combinations : " + str(res))

输出：

The original list is : [‘geekforgeeks’, [5, 4, 3, 4], ‘is’, [‘best’, ‘good’, ‘better’, ‘average’]]

All index Combinations : [[‘geekforgeeks’, 5, ‘is’, ‘best’], [‘geekforgeeks’, 4, ‘is’, ‘good’], [‘geekforgeeks’, 3, ‘is’, ‘better’], [‘geekforgeeks’, 4, ‘is’, ‘average’]]