Python | Sort Tuples in Increasing Order by any key

Given a tuple, sort the list of tuples in increasing order by any key in tuple. Examples:

Input : tuple = [(2, 5), (1, 2), (4, 4), (2, 3)] 
            m = 0
Output : [(1, 2), (2, 3), (2, 5), (4, 4)]
Explanation: Sorted using the 0th index key.

Input :  [(23, 45, 20), (25, 44, 39), (89, 40, 23)]
         m = 2
Output : Sorted: [(23, 45, 20), (89, 40, 23), (25, 44, 39)] 
Explanation: Sorted using the 2nd index key

Given tuples, we need to sort them according to any given key. This can be done using sorted() function where we sort them using key=last and store last as the key index according to which we have to sort the given tuples. Below is the Python implementation of the above approach:

Python

# Python code to sort a list of tuples
# according to given key.

# get the last key.
def last(n):
    return n[m]

# function to sort the tuple
def sort(tuples):

    # We pass used defined function last
    # as a parameter.
    return sorted(tuples, key = last)

# driver code
a = [(23, 45, 20), (25, 44, 39), (89, 40, 23)]
m = 2
print("Sorted:"),
print(sort(a))

Output:

Sorted: [(23, 45, 20), (89, 40, 23), (25, 44, 39)] 

Another  approach  is  using the operator.itemgetter() function from the operator module. The itemgetter() function returns a callable object that can be used to retrieve an item from an object, such as a tuple.

Here is an example of how to use itemgetter() to sort a list of tuples by any key:

Python3

import operator

def sort_tuples(tuples, key):
    return sorted(tuples, key=operator.itemgetter(key))

tuples = [(2, 5), (1, 2), (4, 4), (2, 3)]
key = 0
print(sort_tuples(tuples, key))  # Output: [(1, 2), (2, 3), (2, 5), (4, 4)]

Output

[(1, 2), (2, 5), (2, 3), (4, 4)]

This approach has the advantage of being concise and efficient, as it uses the built-in sorted() function and the itemgetter() function from the operator module. It is also easy to understand and implement.

Note that the itemgetter() function returns a callable object that can be used to retrieve an item from an object, such as a tuple. To sort the tuples, we pass this callable object to the key argument of the `sorted