insertionsort.py

"""
Insertion sort algorithm O(n^2).

Programmed by Aladdin Persson <aladdin.persson at hotmail dot com>
*    2019-01-23 Initial programming
*    2019-03-05 Made code cleaner
"""


def insertionsort(L):
    # loop through all except first element in list
    for index in range(1, len(L)):
        value = L[index]

        position = index - 1

        # inserts the key into the correct place
        while position >= 0 and L[position] > value:
            L[position + 1] = L[position]
            position -= 1

        L[position + 1] = value

    return L


if __name__ == "__main__":
    unsorted = [7, 2, 4, 1, 5, 3]
    sorted = insertionsort(unsorted)
    print(sorted)