Python: Invert a dictionary with unique hashable values

Last update on April 21 2025 12:59:37 (UTC/GMT +8 hours)

72. Invert Dictionary with Unique Values

Write a Python program to invert a dictionary with unique hashable values.

Use dictionary.items() in combination with a list comprehension to create a new dictionary with the values and keys inverted.

Sample Solution:

Python Code:

# Define a function 'test' that takes a dictionary 'students'.
def test(students):
    # Create a new dictionary where the keys and values from 'students' are swapped.
    # The values become keys, and the keys become values in the new dictionary.
    return {value: key for key, value in students.items()}

# Create a dictionary 'students' with names as keys and corresponding grades as values.
students = {
    'Theodore': 10,
    'Mathew': 11,
    'Roxanne': 9,
}

# Call the 'test' function with the 'students' dictionary to swap keys and values.
print(test(students))

Sample Output:

{10: 'Theodore', 11: 'Mathew', 9: 'Roxanne'}

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to invert a dictionary where each value is unique by swapping keys and values.
Write a Python program to create a new dictionary from a given dictionary with unique values, reversing the mapping using dictionary comprehension.
Write a Python program to implement a function that returns the inverse of a dictionary with unique hashable values.
Write a Python program to use the items() method to construct an inverted dictionary from a unique-valued dictionary.

Go to:

Previous: Write a Python program to retrieve the value of the nested key indicated by the given selector list from a dictionary or list.
Next: Write a Python program to convert a list of dictionaries into a list of values corresponding to the specified key.

Python Code Editor: