Custom sorting in list of tuples in Python

Custom sorting in Python allows you to sort a list of tuples based on specific criteria using the sort() method with a key function. This is useful when you need to sort by a particular element within each tuple.

Basic Custom Sorting

The sort() method sorts elements in-place. Use the key parameter to specify which element of the tuple to sort by ?

def tuple_sort(my_tup):
    my_tup.sort(key=lambda x: x[1])
    return my_tup

my_tuple = [('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]

print("Original tuple:")
print(my_tuple)
print("Sorted by second element:")
print(tuple_sort(my_tuple))

Original tuple:
[('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]
Sorted by second element:
[('Jane', 35), ('John', 67), ('Harold', 86), ('Will', 100)]

Sorting by Different Elements

Sort by First Element (Name)

students = [('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]

# Sort by first element (name)
students.sort(key=lambda x: x[0])
print("Sorted by name:")
print(students)

Sorted by name:
[('Harold', 86), ('Jane', 35), ('John', 67), ('Will', 100)]

Sort in Descending Order

students = [('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]

# Sort by score in descending order
students.sort(key=lambda x: x[1], reverse=True)
print("Sorted by score (highest first):")
print(students)

Sorted by score (highest first):
[('Will', 100), ('Harold', 86), ('John', 67), ('Jane', 35)]

Using sorted() Function

Use sorted() to create a new sorted list without modifying the original ?

students = [('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]

# Create new sorted list
sorted_students = sorted(students, key=lambda x: x[1])

print("Original list:")
print(students)
print("New sorted list:")
print(sorted_students)

Original list:
[('Will', 100), ('John', 67), ('Harold', 86), ('Jane', 35)]
New sorted list:
[('Jane', 35), ('John', 67), ('Harold', 86), ('Will', 100)]

Comparison

Conclusion

Use lambda functions with sort() or sorted() to customize tuple sorting. The key parameter specifies which tuple element to sort by, and reverse=True sorts in descending order.