Insertion Sort

insertionsort.py

def insertion_sort(arr):
    for i in range(1, len(arr)):
        cur_val = arr[i]
        
        # indexes of the previous values
        j = i-1
        
        while j>=0 and cur_val < arr[j]:
            arr[j+1] = arr[j]
            j -= 1
        arr[j+1] = cur_val
    
    return arr

insertion_sort([12,4,5,6,7,3,1,15])