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This tutorial explains how to get a key with the maximum value in Python. Since the method has changed from the previous Python versions, it also lists some sample codes to clarify the concepts.

Use operator.itemgetter()the method to get the key with the maximum value

We don't need to create a new list to iterate over the dictionary's (key, value)pairs. We can use stats.iteritems()for this purpose. It (key, value)returns an iterator over the dictionary's pairs.

You can use operator.itemgetter(x)the method to get a callable object that will return xthe element at index from the object. Here, because the object is (key, value)a pair, so operator.itemgetter(1)refers to 1the element at index, that is value.

Since we want a key with the maximum value, we will wrap the method in maxa function.

Basic example code for this method is given below.

import operator

stats = {"key1": 20, "key2": 35, "key3": 44}
max_key = max(stats.iteritems(), key=operator.itemgetter(1))[0]
print(max_key)

Output:

key3

Also, note that , iteritems()which could be raised when adding or removing items from a dictionary RunTimeException, dict.iteritemswas removed in Python 3.

In Python 3.x, use dict.items()the method to get the key of the maximum value in a dictionary.

In Python 3.x, you can use dict.items()the iterate method to iterate over the pairs in a dictionary key-value. It is the same as the iterate method in Python 2 dict.iteritems().

The following is the sample code for this method.

import operator

stats = {"key1": 20, "key2": 35, "key3": 44}
max_key = max(stats.items(), key=operator.itemgetter(1))[0]
print(max_key)

Output:

key3

Generic and memory-efficient solution for getting the key of the maximum value in a dictionary

Interestingly, there is another solution that works for both Python 2 and Python 3. This solution uses lambdathe function to get the key, and maxthe method to ensure that the retrieved keyis the maximal one.

The code for this method is given below.

import operator

stats = {"key1": 20, "key2": 35, "key3": 44}
max_key = max(stats, key=lambda key: stats[key])
print(max_key)

Output:

key3

Use the max()and dict.get()methods to get the key of the maximum value in the dictionary

Another way to solve this problem is to simply use the built-in max()method. It provides statsto get the maximum value, and in order to return the value with the maximum value key, use dict.get()the method.

A sample code is given below.

import operator

stats = {"key1": 20, "key2": 35, "key3": 44}
max_key = max(stats, key=stats.get)
print(max_key)

Output:

key3