編寫sort函數

初版：
lst = [1, 2, 3, 4, 5]


def sort(iterable, reverse=False):
    def comp(a, b):
        flag = a > b if reverse else a < b
        return flag
    ret = []
    for x in iterable:
        for i, y in enumerate(ret):
            if comp(x, y):
                ret.insert(i, x)
                break
        else:
            ret.append(x)
    return ret


print(sort(lst, True))

優化1：
lst1 = [1, 2, 3, 4, 5]


def comp(a, b, reverse=False):
    return a > b if reverse else a < b


def sort(iterable, key=comp):

    ret = []
    for x in iterable:
        for i, y in enumerate(ret):
            if key(x, y, True):
                ret.insert(i, x)
                break
        else:
            ret.append(x)
    return ret


print(sort(lst1))

優化二：
lst2 = [1, 2, 3, 4, 5]


def comp(a, b):
    return a > b


def sort(iterable, key=comp, reverse=False):

    ret = []
    for x in iterable:
        for i, y in enumerate(ret):
            flag = comp(x, y) if reverse else comp(y, x)
            if flag:
                ret.insert(i, x)
                break
        else:
            ret.append(x)
    return ret


print(sort(lst2, key=comp, reverse=True))

優化四：
lst2 = [1, 2, 3, 4, 5]


def sort(iterable, key=lambda a, b: a > b):
    ret = []
    for x in iterable:
        for i, y in enumerate(ret):
            if key(x, y):
                ret.insert(i, x)
                break
        else:
            ret.append(x)
    return ret


print(sort(lst2, lambda a, b: a < b))