Python program to merge two lists and sort it

By Uddeshya Mishra

In this tutorial, we will learn about writing a Python program to merge two lists and then sort it

This tutorial may also be helpful while working on multiple lists.
Python allows merging just by using ‘ + ‘ operator as any number of lists can be merged using this operator. For instance, let us see an example

Merge two lists and then sort it in Python

List_1 = [1,2,3,4,5]
List_2 = [6,7,8,9,10]

Above we have two list mentioned as List_1(which contains numbers 1-5)
and the second list is List_2(which contains numbers 6-10) and now using ‘ + ‘ operator
we will combine the two and assign it into the third list which will be named as List_3

List_3 = List_1 + List_2

Now let us print List_3:

print(List_3)

Output ::
[1,2,3,4,5,6,7,8,9,10]

You can also use the extend Keyword to merge 2 List which changes one of the List as shown below
that is List_1’s elements all got appended to the List_2 which changes the List_2 which will be reflected as
we print the List_3

List_1 = [1,2,3,4,5]
List_2 = [5,6,7,8,9,10]
List_2.extend(List_1)
List_3 = List_2
print(List_3)

Output::

[5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5]

Now our another task is to sort the merged List:
For this, we are free to use the various algorithms built to sort an array of numbers but
Python being a powerful language has a method which sorts the List in an efficient way.

List_3.sort()
print(List_3)

Output::

[1,2,3,4,5,6,7,8,9,10]

Now above what we see is .sort() changed the entire List_3 .
As a matter of fact Python is a Powerful language it also allows you to Sort the
List without affecting the list using the sorted() function which has got a list as an argument.
Seems amazing…isn’t it Let’s see

print(sorted(List_3))

Output:

[1,2,3,4,5,6,7,8,9,10]

Now if you have not used .sort() method enquire about List_3 and what you will find is
List_3 will remain unaffected.

Also read:

• Reverse the elements in a list in Python by its index