python学生分组问题

Question

学生被分成 4 个小组。每个组都分配了一种颜色。每年，当新生在入校时，他们会被平分到这 4 个有颜色的组别中。所有兄弟姐妹，无论年龄大小，都被分配到相同颜色的组。 （你可以假设所有兄弟姐妹都有相同的姓氏。）
编写一个函数divide_students(existing_students, new_students)，它接收现有学生的列表（所有当前就读学校的学生），包括他们的名字，姓氏和group，以及新生列表，包括他们的 first_name和last_name`，并返回一个列表，其中包含两个提供的列表中的所有学生，包括每个学生他们的“first_name”、“last_name”和“group”。所有现有的学生都应保持在活动开始时的同一组中。这些组是：红色、黄色、绿色和蓝色。所有具有相同姓氏的学生都应分配到同一组。学生总数总是能被 4 整除。

existing_students = [
        {"first_name":"Emily", "last_name":"Brown", "group":"Red"}
    ]
    new_students = [
        {"first_name":"Rodney", "last_name":"Bates"},
        {"first_name":"Gaspard", "last_name":"Lenger"},
        {"first_name":"Troy", "last_name":"Liu"}
    ]

existing_students = [
        {"first_name":"Emily", "last_name":"Lenger", "group":"Red"}
    ]
    new_students = [
        {"first_name":"Rodney", "last_name":"Bates"},
        {"first_name":"Gaspard", "last_name":"Lenger"},
        {"first_name":"Troy", "last_name":"Liu"},
        {"first_name":"Sophia", "last_name":"Childs"},
        {"first_name":"Amber", "last_name":"Ash"},
        {"first_name":"Aaron", "last_name":"Hong"},
        {"first_name":"Luke", "last_name":"Malloy"}
    ]
existing_students = [
        {"first_name":"Emily", "last_name":"Lenger", "group":"Red"}
    ]
    new_students = [
        {"first_name":"Rodney", "last_name":"Bates"},
        {"first_name":"Gaspard", "last_name":"Lenger"},
        {"first_name":"Troy", "last_name":"Liu"},
        {"first_name":"Sophia", "last_name":"Childs"},
        {"first_name":"Amber", "last_name":"Malloy"},
        {"first_name":"Aaron", "last_name":"Hong"},
        {"first_name":"Luke", "last_name":"Malloy"}
    ]
existing_students = [
        {"first_name":"Emily", "last_name":"Lenger", "group":"Red"},
        {"first_name":"Rodney", "last_name":"Bates", "group":"Yellow"},
        {"first_name":"Gaspard", "last_name":"Lenger", "group":"Red"},
        {"first_name":"Troy", "last_name":"Liu", "group":"Green"},
        {"first_name":"Sophia", "last_name":"Childs", "group":"Yellow"},
        {"first_name":"Amber", "last_name":"Malloy", "group":"Blue"},
        {"first_name":"Aaron", "last_name":"Hong", "group":"Green"},
        {"first_name":"Luke", "last_name":"Malloy", "group":"Blue"}
    ]
    new_students = [
        {"first_name":"Emil", "last_name":"Malloy"},
        {"first_name":"Paulina", "last_name":"Hart"},
        {"first_name":"Chris", "last_name":"Storm"},
        {"first_name":"Nina", "last_name":"Bates"}
    ]

Answer 1

是这个意思不？首先定义了一个字典 groups 用来存储每个组的学生，然后对于现有学生创建了一个字典 existing_students_dict，用来存储每个学生的姓氏和他们所在的组。对于新生，如果他们的姓氏已经在 existing_students_dict 中，就把他们分配到相同的组，否则就按照颜色顺序分配组并加入 existing_students_dict（你题目没说，我按颜色顺序加了，也就是%4处理，具体你看代码）。最后返回所有学生的列表。
代码如下，有帮助的话记得采纳一下哦！

# last_name为姓
def divide_students(existing_students, new_students):
    groups = {'Red':[], 'Yellow':[], 'Green':[], 'Blue':[]}
    # 刚开始将老生加入到groups中，用于最后遍历输出
    for old_student in existing_students:
        old_group = old_student["group"]
        groups[old_group].append({'first_name': old_student["first_name"], 'last_name': old_student["last_name"],
                                  'group': old_student["group"]})
    # 分离出老生的last_name(姓）和group,转换成字典
    existing_students_dict = {student['last_name']:student['group'] for student in existing_students}
    # 对于新生便历判断
    for student in new_students:
        last_name = student['last_name']
        first_name = student['first_name']
        # 姓在existing_students_dict字典中，组是老生同姓的组
        if last_name in existing_students_dict:
            group = existing_students_dict[last_name]
        else:
            # 不在老生组中的姓的学生，按颜色顺序分组
            group = list(groups.keys())[len(existing_students_dict) % 4]
            existing_students_dict[last_name] = group
        # 将新生加入到groups中
        groups[group].append({'first_name':first_name, 'last_name':last_name, 'group':group})

    result = []
    # 遍历groups中的所有值，这个值为列表，然后遍历列表，将每个学生信息加入到result列表中返回
    for group in groups.values():
        for student in group:
            result.append(student)

    return result


existing_students = [
        {"first_name":"Emily", "last_name":"Lenger", "group":"Red"}
    ]
new_students = [
    {"first_name":"Rodney", "last_name":"Bates"},
    {"first_name":"Gaspard", "last_name":"Lenger"},
    {"first_name":"Troy", "last_name":"Liu"},
    {"first_name":"Sophia", "last_name":"Childs"},
    {"first_name":"Amber", "last_name":"Ash"},
    {"first_name":"Aaron", "last_name":"Hong"},
    {"first_name":"Luke", "last_name":"Malloy"}
]

print(divide_students(existing_students, new_students))