python sorts

sort.py

def selection_sort(arr):
    i = 0
    j = 0
    while i < len(arr) - 1:
        j = i + 1
        while j < len(arr):
            if arr[i] > arr[j]:
                arr[i], arr[j] = arr[j], arr[i]
            j += 1
        i += 1

    return arr


def insertion_sort(arr):
    i = 0
    j = 0
    while i < len(arr) - 1:
        j = i + 1
        while j > 0 and arr[j - 1] > arr[j]:
            arr[j - 1], arr[j] = arr[j], arr[j - 1]
            j -= 1
        i += 1

    return arr


def bubble_sort(arr):
    i = len(arr)
    j = 0
    while i > 0:
        j = 0
        while j < i - 1:
            if arr[j] > arr[j + 1]:
                arr[j + 1], arr[j] = arr[j], arr[j + 1]
            j += 1
        i -= 1

    return arr


def merge_sort(arr):
    if len(arr) == 1:
        return arr
    mid = len(arr) / 2

    left = merge_sort(arr[:mid])
    right = merge_sort(arr[mid:])

    return _merge(left, right)


def _merge(left, right):
    result = []
    i = 0
    j = 0
    while i < len(left) and j < len(right):
        if left[i] < right[j]:
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1

    if (i != len(left)):
        result.extend(left[i:])
    if (j != len(right)):
        result.extend(right[j:])
    return result


def quick_sort(arr):
    if len(arr) <= 1:
        return arr

    left = []
    right = []
    pivot = arr[0]
    i = 1

    while i < len(arr):
        if arr[i] <= pivot:
            left.append(arr[i])
        else:
            right.append(arr[i])
        i += 1

    return quick_sort(left) + [pivot] + quick_sort(right)