Quick Sort

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    else:
        pivot = arr[0]  # select first element as the base number
        less_than_pivot = [x for x in arr[1:] if x <= pivot]  # elements less than the base
        greater_than_pivot = [x for x in arr[1:] if x > pivot]  # elements bigger than the base
        return quick_sort(less_than_pivot) + [pivot] + quick_sort(greater_than_pivot)  # Beautiful ~


# Sample
data = [54, 26, 93, 17, 77, 31, 44, 55, 20]
print("Original:", data)
sorted_data = quick_sort(data)
print("After:", sorted_data)
# Original: [54, 26, 93, 17, 77, 31, 44, 55, 20]
# After: [17, 20, 26, 31, 44, 54, 55, 77, 93]