Sort List of Tuples in Python

Sort List of Tuples in Python

Vaibhhav Khetarpal Oct-17, 2021 Feb-26, 2021 Python Python Tuple
  1. Use the list.sort() Function to Sort List of Tuples in Python
  2. Use the Bubble Sort Algorithm to Sort the List of Tuples in Python

In Python, multiple items can be stored in a single variable using Tuples. A list of Tuples can be sorted like a list of integers.

This tutorial will discuss different methods to sort a list of tuples based on the first, second, or ith element in the tuples.

Use the list.sort() Function to Sort List of Tuples in Python

The list.sort() function sorts the elements of a list in ascending or descending order. Its key parameter specifies the value to be used in the sorting. key shall be a function or other callables that could be applied to each list element.

The following code sorts the tuples based on the second element in all the tuples.

list_students = [('Vaibhhav',86), ('Manav',91) , ('Rajesh',88) , ('Sam',84), ('Richie',89)]

#sort by second element of tuple
list_students.sort(key = lambda x: x[1])   #index 1 means second element

print(list_students)

Output:

[('Sam',84), ('Vaibhhav',86), ('Rajesh',88), ('Richie',89), ('Manav',91)]

The order can be reversed to descending by setting the reverse parameter of the sort() method to be True.

The following code sorts the list of tuples in descending order by using the reverse parameter.

list_students = [('Vaibhhav',86), ('Manav',91) , ('Rajesh',88) , ('Sam',84), ('Richie',89)]

#sort by second element of tuple
list_students.sort(key = lambda x: x[1], reverse=True)

print(list_students)

Output:

[('Manav',91), ('Richie',89), ('Rajesh',88), ('Vaibhhav',86), ('Sam',84)]

Use the Bubble Sort Algorithm to Sort the List of Tuples in Python

Bubble Sort is one of the simplest sorting algorithms; it works by swapping the adjacent elements in a list if they are in the wrong order and repeats this step until the list is sorted.

The following code sorts the tuples based on the second element and uses the bubble sort algorithm.

list_ = [('Vaibhhav',86), ('Manav',91) , ('Rajesh',88) , ('Sam',84), ('Richie',89)]

#sort by second element of tuple
pos = 1
list_length = len(list_)

for i in range(0, list_length):
    for j in range(0, list_length-i-1):  
        if (list_[j][pos] > list_[j + 1][pos]):  
            temp = list_[j]  
            list_[j]= list_[j + 1]  
            list_[j + 1]= temp  

print(list_)

Output:

[('Sam',84), ('Vaibhhav',86), ('Rajesh',88), ('Richie',89), ('Manav',91)]

The pos variable specifies the position by which sorting has to be carried out, which in this case, is the second element.

We can also use the first element to sort the list of tuples. The following program implements this.

list_ = [('Vaibhhav',86), ('Manav',91) , ('Rajesh',88) , ('Sam',84), ('Richie',89)]

#sort by first element of tuple
pos = 0
list_length = len(list_)  
for i in range(0, list_length):  
    for j in range(0, list_length-i-1):  
        if (list_[j][pos] > list_[j + 1][pos]):  
            temp = list_[j]  
            list_[j]= list_[j + 1]  
            list_[j + 1]= temp  

print(list_)

Output:

[('Manav',91), ('Rajesh',88), ('Richie',89), ('Sam',84), ('Vaibhhav',86)]

Related Article - Python Tuple

  • Named Tuple in Python
  • Iterate Through a Tuple in Python
  • Create a List of Tuples From Multiple Lists and Tuples in Python
  • Tuple Comprehension in Python
  • Convert Tuple to List in Python
  • Convert Tuple to String in Python