请问如何编写python成绩排序

Question

该怎么在下面的代码里添加一个可以升序和降序的成绩排序功能呀

from search import search_by_id

stat_submenu = '''

    5 统计 ---|---  1 学生总分   
              |---  2 单科总成绩、平均分
              |---  3 单科最高分
              |---  4 总成绩排序
              |---  0 返回

'''

def scores_sum(db, sid):
    sum = 0
    if search_by_id(db, sid) == {}:
        print('  - %s does not exist.' % sid)
        sum = -1
    else:
        for i in db:
            if i['studentID'] == sid:
                sum = i['score_1'] + i['score_2'] + i['score_3']
    return sum

def object_sum(db, object_n):
    avg = 0
    sum = 0
    total = len(db)
    for i in db:
        sum += float(i[object_n])
    avg = sum / total
    return sum, avg

def object_max(db, object_n):
    max = 0
    for i in db:
        temp = float(i[object_n])
        if temp > max:
            max = temp
    return max

def db_stat(db):
    temp_db = db
    while True:
        print(stat_submenu)
        option = input('  > Enter your option:')
        if option == '0':
            break
        elif option == '1':
            sid = input('  >> Student ID:')
            sum = scores_sum(db, sid.strip())
            if sum != -1:
                print('  - Sum_Score of %s is %f' % (sid, sum))
            continue
        elif option == '2':
            object_name = input('  > Object name:')
            sum, avg = object_sum(db, object_name.strip())
            print('  - Sum of the object %s is %f' % (object_name, sum))
            print('  - Average of the object %s is %f' % (object_name, avg))
            continue
        elif option == '3':
            object_name = input('  > Object name:')
            max = object_max(db, object_name.strip())
            print('  - The maximum of the object %s is %f' % (object_name, max))
            continue
        elif option == '4':
            print('  - To be coded.')
            continue
        else:
            print('  - Inputting WRONG!')
            continue


if __name__ == '__main__':
    db_stat([])
    pass

Answer 1

from search import search_by_id
 
stat_submenu = '''
    5 统计 ---|---  1 学生总分   
              |---  2 单科总成绩、平均分
              |---  3 单科最高分
              |---  4 总成绩排序
              |---  0 返回
'''
 
def scores_sum(db, sid):
    sum = 0
    if search_by_id(db, sid) == {}:
        print('  - %s does not exist.' % sid)
        sum = -1
    else:
        for i in db:
            if i['studentID'] == sid:
                sum = i['score_1'] + i['score_2'] + i['score_3']
    return sum
 
def object_sum(db, object_n):
    avg = 0
    sum = 0
    total = len(db)
    for i in db:
        sum += float(i[object_n])
    avg = sum / total
    return sum, avg
 
def object_max(db, object_n):
    max = 0
    for i in db:
        temp = float(i[object_n])
        if temp > max:
            max = temp
    return max

def sort_sum(db):
    l = list()
    d = dict()
    for i in db:
        d[i['studentID']] = i['score_1'] + i['score_2'] + i['score_3']
    
    # 升序
    l.append(sorted(d.items(), key=lambda s:s[1]))
    # 降序
    l.append(sorted(d.items(), key=lambda s:s[1], reverse=True))
    return l

def db_stat(db):
    temp_db = db
    while True:
        print(stat_submenu)
        option = input('  > Enter your option:')
        if option == '0':
            break
        elif option == '1':
            sid = input('  >> Student ID:')
            sum = scores_sum(db, sid.strip())
            if sum != -1:
                print('  - Sum_Score of %s is %f' % (sid, sum))
            continue
        elif option == '2':
            object_name = input('  > Object name:')
            sum, avg = object_sum(db, object_name.strip())
            print('  - Sum of the object %s is %f' % (object_name, sum))
            print('  - Average of the object %s is %f' % (object_name, avg))
            continue
        elif option == '3':
            object_name = input('  > Object name:')
            max = object_max(db, object_name.strip())
            print('  - The maximum of the object %s is %f' % (object_name, max))
            continue
        elif option == '4':
            print(sort_sum(db))
            continue
        else:
            print('  - Inputting WRONG!')
            continue
 
 
if __name__ == '__main__':
    db_stat([])
    pass