Python: Sort a list of tuples using Lambda

Last update on April 22 2025 12:52:14 (UTC/GMT +8 hours)

3. Tuple Sorting Lambda

Write a Python program to sort a list of tuples using Lambda.

Sample Solution:

Python Code :

# Create a list of tuples named 'subject_marks', each tuple containing a subject and its corresponding marks
subject_marks = [('English', 88), ('Science', 90), ('Maths', 97), ('Social sciences', 82)]

# Display the original list of tuples to the console
print("Original list of tuples:")
print(subject_marks)

# Sort the 'subject_marks' list of tuples based on the second element of each tuple (the marks),
# using a lambda function as the sorting key to extract the second element
subject_marks.sort(key=lambda x: x[1])

# Display the sorted list of tuples to the console
print("\nSorting the List of Tuples:")
print(subject_marks)

Sample Output:

Original list of tuples:
[('English', 88), ('Science', 90), ('Maths', 97), ('Social sciences', 82)]

Sorting the List of Tuples:
[('Social sciences', 82), ('English', 88), ('Science', 90), ('Maths', 97)]

Explanation:

In the exercise above -

subject_marks = [('English', 88), ('Science', 90), ('Maths', 97), ('Social sciences', 82)]: Initializes a list of tuples named 'subject_marks'. Each tuple contains a subject (string) as its first element and the corresponding marks (integer) as its second element.
print("Original list of tuples:"): Prints a message indicating that the following output will display the original list of tuples.
print(subject_marks): Displays the original list of tuples ('subject_marks') to the console.
subject_marks.sort(key=lambda x: x[1]): Sorts the list of tuples (subject_marks) based on the second element of each tuple (i.e., the marks). It uses a lambda function as the sorting key, which extracts the second element (x[1]) for sorting purposes.
print("\nSorting the List of Tuples:"): Prints a message indicating that the following output will display the sorted list of tuples.
print(subject_marks): Displays the sorted list of tuples (now sorted based on marks) to the console.

For more Practice: Solve these Related Problems:

Write a Python program to sort a list of tuples by the length of the string element using lambda.
Write a Python program to sort a list of tuples by the second element in descending order using lambda.
Write a Python program to sort a list of tuples by the sum of ASCII values of characters in the first element using lambda.
Write a Python program to sort a list of tuples by the difference between the second element and the string length of the first element using lambda.

Go to:

Previous: Write a Python program to create a function that takes one argument, and that argument will be multiplied with an unknown given number.
Next: Write a Python program to sort a list of dictionaries using Lambda.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.