How does Python insertion sort work?

Question

Here\'s a Python implementation of insertion sort, I tried to follow the values on paper but once the counting variable i gets bigger than len(s) I don\'t know what to do, h

Answer 1

Try this one, works for both increasing and decreasing order:

import operator

def insertion_sort(arr, reverse=False):
    # check if array is empty or not
    if arr is None:
        raise TypeError("Data cannot be none")

    n = len(arr)
    # if length of array is less than two it is already sorted
    if n < 2:
        return arr

    lgt = operator.gt if reverse else operator.lt

    # Traverse through 1 to len(arr)
    for i in range(1, n):
        key = arr[i]
        j = i-1
        while j >= 0 and lgt(key, arr[j]):
            arr[j+1] = arr[j]
            j -= 1
        arr[j+1] = key
    return arr

li = [1, 4, 8, 9, 42, 0, 36]
print(insertion_sort(li))