The Quicksort algorithm simple and readable implementation in Python

quick_sort.py

from typing import List, Tuple


def quick_sort(lst: List[int]) -> List[int]:
    """The Quicksort algorithm.

    Wikipedia: https://en.wikipedia.org/wiki/Quicksort
    """
    if len(lst) < 2:
        return lst

    pivot = lst[-1]
    smaller, bigger = partition(lst, pivot)

    bigger = quick_sort(bigger)
    smaller = quick_sort(smaller)

    return smaller + [pivot] + bigger


def partition(lst: List[int], pivot: int) -> Tuple[List[int], List[int]]:
    """Partition the list into 2 parts based on their relation with `pivot`.

    `left` holds items smaller than `pivot`, and right holds items bigger than
    `pivot`.
    This function doesn't consider the last item when creating the partitions.
    """
    left, right = [], []

    for i in range(len(lst) - 1):
        if lst[i] < pivot:
            left.append(lst[i])
        else:
            right.append(lst[i])

    return left, right