Python | Get key with maximum value in Dictionary

Given a dictionary, the task is to find the key having the maximum value. 

Examples :

Input: {'Audi':100, 'BMW':1292, 'Jaguar': 210000, 'Hyundai' : 88}
Output: Jaguar

Input:  {'Geeks':1900, 'for':1292, 'geek' : 88}
Output:  Geeks

Method #1: Using max() function

Python3

# Python code to find key with Maximum value in Dictionary

# Dictionary Initialization
Tv = {'BreakingBad':100, 'GameOfThrones':1292, 'TMKUC' : 88}

Keymax = max(zip(Tv.values(), Tv.keys()))[1]
print(Keymax)

Output

GameOfThrones

Time complexity: O(n log n), where n is the number of key-value pairs in the dictionary.
Auxiliary space: O(1), as we are not using any extra data structure to store the key with maximum value.

Method 2: Using max() with lambda function

Python3

# Python code to find key with Maximum value in Dictionary

# Dictionary Initialization
Tv = {'BreakingBad':100, 'GameOfThrones':1292, 'TMKUC' : 88}

Keymax = max(Tv, key= lambda x: Tv[x])
print(Keymax)

Output

GameOfThrones

Time complexity: O(n log n), where n is the number of keys in the dictionary. 
Auxiliary space: O(1), as the code only uses a constant amount of extra space to store the maximum key.

Method 3: Using operator 

Python3

# Python code to find key with
# Maximum value in Dictionary
import operator

# Dictionary Initialization
Car = {'Audi':100, 'BMW':1292, 'Jaguar': 210000, 'Hyundai' : 88}

# Getting max item
keyMax = max(Car.items(), key = operator.itemgetter(1))[0]
print(keyMax)

Output

Jaguar

Time complexity: O(nlogn), where n is the number of items in the dictionary.
Auxiliary space: O(1), as the space used is constant and does not depend on the size of the input dictionary.

Method 4:

Python3

# Python code to find key with Maximum value in Dictionary

# Dictionary Initialization
Company = {'GFG':10000, 'Hashd':2292, 'Infy': 200}

# taking list of car values in v
v = list(Company.values())

# taking list of car keys in v
k = list(Company.keys())

print(k[v.index(max(v))])

Output

GFG

Time complexity: O(n), where n is the number of elements in the dictionary.
Auxiliary space: O(n), since two lists (v and k) are created of size n.

Method 5: Using iteration:

Here is an additional approach that you could use to find the key with the maximum value in a dictionary:

1. Initialize a variable max_key to the first key in the dictionary.
2. Iterate over the keys in the dictionary using a for loop.
3. For each key, check if the value of the key is greater than the value of the current max_key. If it is, update max_key to be the current key.
4. After the for loop has completed, max_key will contain the key with the maximum value in the dictionary.

Implementation:

Python3

# Initialize the dictionary
d = {'a': 10, 'b': 20, 'c': 30, 'd': 40, 'e': 50}

# Initialize max_key to the first key in the dictionary
max_key = next(iter(d))

# Iterate over the keys in the dictionary
for key in d:
    # If the value of the current key is greater than the value of max_key, update max_key
    if d[key] > d[max_key]:
        max_key = key

# Print the key with the maximum value
print(max_key)
#This code is contributed by Edula Vinay Kumar Reddy

Output

e

Time complexity: O(n), where n is the number of keys in the dictionary.
Auxiliary space: O(1)