Find Key with Max Value in Dictionary in Python: Simple Guide

Use the max() function with a key argument to find the dictionary key that has the highest value. For example, max(your_dict, key=your_dict.get) returns the key with the maximum value.

Syntax

The syntax to find the key with the maximum value in a dictionary is:

• max(dictionary, key=dictionary.get)

Here, dictionary is your dictionary variable.

The max() function finds the maximum element based on the function given in key. Using dictionary.get tells it to compare dictionary values.

python

max_key = max(dictionary, key=dictionary.get)

Example

This example shows how to find the key with the highest value in a dictionary of fruits and their quantities.

python

fruits = {'apple': 10, 'banana': 25, 'orange': 15}
max_fruit = max(fruits, key=fruits.get)
print(max_fruit)

Output

banana

Common Pitfalls

One common mistake is trying to use max() without the key argument, which returns the maximum key alphabetically, not by value.

Another mistake is using max(dictionary.values()) which returns the maximum value but not the key.

python

fruits = {'apple': 10, 'banana': 25, 'orange': 15}

# Wrong: returns max key alphabetically
wrong_key = max(fruits)
print(wrong_key)  # Output: orange

# Wrong: returns max value only
max_value = max(fruits.values())
print(max_value)  # Output: 25

# Right: returns key with max value
max_key = max(fruits, key=fruits.get)
print(max_key)  # Output: banana

Output

orange
25
banana

Quick Reference

• max(dictionary, key=dictionary.get): Returns key with highest value.
• dictionary.get: Function to get value for each key.
• Use min(dictionary, key=dictionary.get) to find key with smallest value.

Key Takeaways

Use max(dictionary, key=dictionary.get) to find the key with the highest value.

Without the key argument, max() returns the maximum key alphabetically, not by value.

max(dictionary.values()) returns the maximum value, not the key.

You can use min(dictionary, key=dictionary.get) to find the key with the smallest value.