In this tutorial, we will discuss a Python program for insertion sort algorithm to sort an array of numbers in ascending order.

Before going to the program first, let us understand what is Insertion Sort.

Insertion Sort:

• Insertion sort is a simple sorting algorithm that builds the final sorted array one item at a time.

Related: Python program for Bubble Sort

Program code for Insertion Sort in Python

# Insertion Sort in Python
def insertion_sort(arr):
    for i in range(1, len(arr)):
        key = arr[i]
        j = i - 1
        while j >= 0 and key < arr[j]:
            arr[j + 1] = arr[j]
            j -= 1
        arr[j + 1] = key

arr = [12, 11, 13, 5, 6]
insertion_sort(arr)
print("Sorted array:", arr)

Explanation

1. Function Definition: The insertion_sort function takes an array arr as input and sorts it in ascending order using the insertion sort algorithm.
2. Main Program: The program defines an unsorted array and sorts it using the insertion_sort function. It then prints the sorted array.

Output

• When you run the above program, it will sort the array using insertion sort and print the sorted result.

Conclusion

• In this tutorial, we learned how to implement the insertion sort algorithm in Python.
• Understanding this concept is essential for solving various sorting problems and enhancing your programming skills.