Insertion Sort Program in Python

Python - Insertion Sort

In the tutorial, we will implement Insertion Sort Algorithm in Python.

We will write a function named insertion_sort() which takes list as argument and sorts this list using Insertion Sort algorithm. Also, by default, this insertion_sort() function sorts the list in ascending order. To get the descending order, all you have to do is just reverse the list.

Python Program

def insertion_sort(nlist):
    for i in range(1, len(nlist)):
        temp = nlist[i]
        j = i - 1
        while (j >= 0 and temp < nlist[j]):
            nlist[j + 1] = nlist[j]
            j = j - 1
        nlist[j + 1] = temp

#input list
alist = [1, 74, 96, 5, 42, 63]
print('Input List\n', alist)

#sort list
insertion_sort(alist)
print('Sorted List\n', alist)

Output

Input List
 [1, 74, 96, 5, 42, 63]
Sorted List
 [1, 5, 42, 63, 74, 96]

Conclusion

In this tutorial of Python Examples, we learned how to implement Insertion Sort algorithm in Python.