Python program to sort a dictionary list based on the maximum value

Given list with dictionaries as elements, write a Python program to sort the dictionary on the basis maximum value in a key value pair of a dictionary. In simpler terms, first each element of a list (which is a dictionary) will be checked, meaning each key value pair will be compared to find the element with maximum value. Then, in the list sorting will be done on the basis of which element contains maximum value so obtained.

Examples:

Input : test_list = [{1:5, 6:7, 9:1}, {2:6, 9:10, 1:4}, {6:5, 9:3, 1:6}] 
Output : [{6: 5, 9: 3, 1: 6}, {1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}] 
Explanation : 6 < 7 < 10, is maximum elements ordering. 

• 6 is maximum in dictionary having 5, 3, 6 as values in a key-value pair
• 7 is maximum in dictionary having 5, 7, 1 as values in a key-value pair and
• 10 is maximum in dictionary having 6, 10, 4 as values in a key-value pair.

Input : test_list = [{1:5, 6:7, 9:1}, {2:6, 9:10, 1:4}] 
Output : [{1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}] 
Explanation : 7 < 10,  

• 7 is maximum in dictionary having 5, 7, 1 as values in a key-value pair
• 10 is maximum in dictionary having 6, 10, 4 as values in a key-value pair
  

Method #1 : Using values(), max() and sort()

In this, we perform the task of in-place sorting using sort(), get maximum value using max(), and values using values(). External function is passed as parameter to achieve required functionality.

Example:

Python3

# getting max value
def get_max(dicts):
    return max(list(dicts.values()))


# initializing list
test_list = [{1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}, {6: 5, 9: 3, 1: 6}]

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

# sorting dictionary list by maximum value
test_list.sort(key=get_max)

# printing result
print("Sorted List : " + str(test_list))

Output:

The original list is : [{1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}, {6: 5, 9: 3, 1: 6}]

Sorted List : [{6: 5, 9: 3, 1: 6}, {1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}]

Method #2 : Using sorted(), lambda, max() and values()

In this, we perform sorting using sorted() and lambda function, to provide single statement filtering rather than calling the external function.

Example:

Python3

# initializing list
test_list = [{1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}, {6: 5, 9: 3, 1: 6}]

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

# sorting dictionary list by maximum value
# one statement sort
res = sorted(test_list, key=lambda dicts: max(list(dicts.values())))

# printing result
print("Sorted List : " + str(res))

Output:

The original list is : [{1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}, {6: 5, 9: 3, 1: 6}]

Sorted List : [{6: 5, 9: 3, 1: 6}, {1: 5, 6: 7, 9: 1}, {2: 6, 9: 10, 1: 4}]