Python – Extract Maximum Keys’ value dictionaries

Given a dictionary, extract all the dictionary which contains a any key which has maximum values among other keys in dictionary list.

Input : [{“Gfg” : 3, “is” : 7, “Best” : 8}, {“Gfg” : 9, “is” : 2, “Best” : 9}, {“Gfg” : 5, “is” : 4, “Best” : 10}, {“Gfg” : 3, “is” : 6, “Best” : 14}] Output : [{“Gfg” : 3, “is” : 7, “Best” : 8}, {“Gfg” : 9, “is” : 2, “Best” : 9}, {“Gfg” : 3, “is” : 6, “Best” : 14}] Explanation : “Gfg” has 9 as best, “is” has 7 and “Best” has 14, those dictionaries are extracted. Input : [{“Gfg” : 3, “is” : 7, “Best” : 8}, {“Gfg” : 9, “is” : 2, “Best” : 9}, {“Gfg” : 5, “is” : 4, “Best” : 10}, {“Gfg” : 3, “is” : 6, “Best” : 16}] Output : [{“Gfg” : 3, “is” : 7, “Best” : 8}, {“Gfg” : 9, “is” : 2, “Best” : 9}, {“Gfg” : 3, “is” : 6, “Best” : 16}] Explanation : “Gfg” has 9 as best, “is” has 7 and “Best” has 16, those dictionaries are extracted.

Method : Using max() + filter() + lambda

The combination of above functionalities can be used to solve this problem. In this, first maximum is extracted for particular key and then all dictionaries matching maximum key are extracted. This is carries out for all the keys.

Python3

# Python3 code to demonstrate working of
# Extract Maximum Keys' value dictionaries
# Using max() + filter() + lambda

# initializing list
test_list = [{"Gfg" : 3, "is" : 7, "Best" : 8},
             {"Gfg" : 9, "is" : 2, "Best" : 9},
             {"Gfg" : 5, "is" : 4, "Best" : 10},
             {"Gfg" : 3, "is" : 6, "Best" : 8}]

# printing original list
print("The original list : " + str(test_list))

res = []

# getting all keys
all_keys = list(test_list[0].keys())
for sub in all_keys:

    # extracting maximum of each keys
    temp = max(test_list, key = lambda ele: ele[sub])
    res_key = list(filter(lambda ele: ele[sub] == temp[sub], test_list))
    res.append(res_key)

# printing result
print("The extracted maximum key values dictionaries : " + str(res))

Output

The original list : [{'Gfg': 3, 'is': 7, 'Best': 8}, {'Gfg': 9, 'is': 2, 'Best': 9}, {'Gfg': 5, 'is': 4, 'Best': 10}, {'Gfg': 3, 'is': 6, 'Best': 8}]
The extracted maximum key values dictionaries : [[{'Gfg': 9, 'is': 2, 'Best': 9}], [{'Gfg': 3, 'is': 7, 'Best': 8}], [{'Gfg': 5, 'is': 4, 'Best': 10}]]

Time Complexity: O(n)
Auxiliary Space: O(n)