Python - 字典值列表中第 K 个索引处具有最大元素的键

给定一个值作为列表的字典，任务是编写一个Python程序，通过比较每个列表的元素来获取第 K^个索引处具有最大元素的键。

Input : test_dict = {‘Gfg’ : [4, 6, 8, 2], 
‘is’ : [1, 4, 5, 9], 
‘best’ :[2, 3, 4, 10], 
‘for’ :[4, 5, 2, 1], 
‘geeks’ :[2, 10, 1, 8]}, K = 3 
Output : best 
Explanation : 2, 9, 10, 1, 8 are elements and 10 is maximum.
 

Input : test_dict = {‘Gfg’ : [4, 6, 8, 2], 
‘is’ : [1, 4, 5, 9], 
‘best’ :[2, 3, 4, 10], 
‘for’ :[4, 5, 2, 1], 
‘geeks’ :[2, 10, 1, 8]}, K = 2 
Output : Gfg 
Explanation : 8, 5, 4, 2, 1 are elements and 8 is maximum. 
 

方法一： 使用sorted()， 字典理解和lambda

在此，我们对索引 K 值处的所有列表元素及其 Key 进行反向排序，然后输出提取的最大值的键。

例子：

Python3

# Python3 code to demonstrate working of
# Key with Maximum element at Kth index 
# in Dictionary Value List Using sorted()
# + dictionary comprehension + lambda
  
# initializing dictionary
test_dict = {'Gfg': [4, 6],
             'is': [1, 4, 5, 9, 4, 5, 7],
             'best': [2, 3, 4, 10],
             'for': [4],
             'geeks': [2, 10, 1, 10]}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing K
K = 3
  
# sorted sorting all the values in reverse order
# Maximum element is found at 1st position
temp = sorted({key: val[K] if K <= len(val) else -1 for key,
               val in test_dict.items()}.items(),
              key=lambda sub: sub[1], reverse=True)
  
# getting all maximum keys in case of multiple
res = []
for idx, ele in enumerate(temp):
    res.append(temp[idx][0])
    if temp[idx][1] != temp[idx + 1][1]:
        break
  
# printing result
print("The extracted key : " + str(res))

输出：

The original dictionary is : {‘Gfg’: [4, 6, 8, 2, 5, 6], ‘is’: [1], ‘best’: [2, 3, 4, 10], ‘for’: [4, 5, 2, 1], ‘geeks’: [2, 10, 1, 10]}

The extracted key : [‘best’, ‘geeks’]

方法 2：使用max()和生成器表达式

在这里，我们使用 max() 执行获取最大值的任务，并且生成器表达式用于迭代字典中的所有键。下一步，我们得到与 K 处最大元素匹配的所有键。

例子：

蟒蛇3

# Python3 code to demonstrate working of
# Key with Maximum element at Kth index 
# in Dictionary Value List Using max()
# + generator expression
  
# initializing dictionary
test_dict = {'Gfg': [4, 6, 8, 2, 5, 6],
             'is': [1],
             'best': [2, 3, 4, 10],
             'for': [4, 5, 2, 1],
             'geeks': [2, 10, 1, 10]}
  
# printing original dictionary
print("The original dictionary is : " + str(test_dict))
  
# initializing K
K = 3
  
# sorted sorting all the values in reverse order
# Maximum element is found at 1st position
# getting maximum
temp = max(test_dict[key][K] if K < len(
    test_dict[key]) else -1 for key in test_dict)
  
# getting all keys with maximum.
res = []
for key in test_dict:
    if K < len(test_dict[key]) and test_dict[key][K] == temp:
        res.append(key)
  
# printing result
print("The extracted key : " + str(res))

输出：

The original dictionary is : {‘Gfg’: [4, 6, 8, 2, 5, 6], ‘is’: [1], ‘best’: [2, 3, 4, 10], ‘for’: [4, 5, 2, 1], ‘geeks’: [2, 10, 1, 10]}

The extracted key : [‘best’, ‘geeks’]