Sorting a List of Tuples by First and Second Element in Python

A list of tuples is a list contains a collection of tuples, for example:

[(4, 8, 6), (7, 3, 9), (1, 1, 3)]

This article will guide you through sorting a list of tuples by the first and second elements.

Sorting by First Element

You can use the sorted() function with a lambda function as the key To sort a list of tuples by the first element.

Here is an example:

data = [('banana', 3), ('apple', 2), ('orange', 5)]

sorted_data = sorted(data, key=lambda x: x[0])

print(sorted_data)

Output:

[('apple', 2), ('banana', 3), ('orange', 5)]

As you can see, The key parameter is set to a lambda function that extracts the first element (x[0]) from each tuple.

Sorting by Second Element

To sort the list of tuples by the second element, you can modify the lambda function to access the second element (x[1]). Here's an example:

data = [('banana', 3), ('apple', 2), ('orange', 5)]

sorted_data = sorted(data, key=lambda x: x[1])

print(sorted_data)

Output:

[('apple', 2), ('banana', 3), ('orange', 5)]

Sorting by Multiple Elements

You can also sort by multiple elements using a tuple as the key. You can see the below example.

data = [('banana', 3), ('apple', 2), ('orange', 5)]

sorted_data = sorted(data, key=lambda x: (x[0], x[1]))

print(sorted_data)

The sorting process will prioritize the first and, subsequently, the second elements.

Output:

[('apple', 2), ('banana', 3), ('orange', 5)]

Conclusion

Here, we have learned how to sort a list of tuples by first, second element, and multiple elements using the sorted() function.