回到他的需求：

1，可以新增记录，2，可以查询，3，可以全部展示，4，可以删除，5，可以更新。

那么我们先把大框架搭起来：

class Contact(object):    def __init__(self):        pass    def search_contact(self, args):        pass    def display_all(self):        pass    def update_number(self, new_number):        pass    def delete_contact(self):        pass

 看，一个类，Contact，还有包括初始化在内的5个方法，已经涵盖了我们的要求了

然后搭好所有的类

别忘了：

1，你要在一个list里保存所有的信息，所以要定义在class中

2，search和display应该是classmethod

3，update应他要求，也做成了classmethod

class Contact(object):    con = []    def __init__(self):        self.f = None        self.l = None        self.n = None        self.a = None        self.list = []    def setup_ins(self):        '''f as first name,l as last name,n as number,a,as address,con as all_contacts'''        self.f = str(input('input first name:'))        self.l = str(input('input last name:'))        self.n = str(input('input number:'))        self.a = str(input('input address:'))        # print(self.f, self.l, self.n, self.a)        if self.f == '' or self.l == '' or self.n == '' or self.a == '':            return 0        else:            self.list.extend([self.f, self.l, self.n, self.a])            Contact.con.append(self.list)    @classmethod    def search_contact(cls, args):        if args == '':            return 0        else:            for obj in Contact.con:  # first list                if args in obj:  # searching in second list                    print(obj)                    return 1                else:                    print('no such a record!')    @classmethod    def display_all(cls):        for obj in Contact.con:            print(obj)    @classmethod    def update_number(cls, old_number, new_number):        for obj in Contact.con:  # first list            if old_number in obj:  # searching in second list                i = Contact.con.index(obj)                j = obj.index(old_number)                Contact.con[i][j] = new_number                return 1            else:                return 0    def delete_contact(self):        i = Contact.con.index(self.list)        Contact.con.pop(i)

 下面是调用的部分：

while 1:    print('<<<<<<<<<<<<<<<<<<<<<
     
      >>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(1)add record>>>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(2)search record>>>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(3)show all record>>>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(4)delete record>>>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(5)update record >>>>>>>>>>>>>>>>>>>>>>>')    print('<<<<<<<<<<<<<<<<<<<<<<(6)exit >>>>>>>>>>>>>>>>>>>>>>>')    choice = input('make your choice(1/2/3/4/5/6):')    # print(type(choice))  # debug    if choice == '1':        user_name = str(input('type a user_name:'))        res = 1        exec('%s = Contact()' % user_name)        exec('res = %s.setup_ins()' % user_name)        if res == 0:            print('error please completely input!')            exec('del(%s)' % user_name)        continue        # Contact.display_all()  # debug    elif choice == '2':        search_obj = str(input('what do you want to search:'))        res = Contact.search_contact(search_obj)        if res == 0:            print('input something!')        continue    elif choice == '3':        Contact.display_all()        continue    elif choice == '4':        delete_name = str(input('who do you want to delete:'))        exec('%s.delete_contact()' % delete_name)        continue    elif choice == '5':        old_num = str(input('type old number:'))        new_num = str(input('type new number:'))        res = Contact.update_number(old_num, new_num)        if res == 1:            print('success!')        else:            print('failed!')        continue    elif choice == '6':        print('bye!')        break    else:        print('wrong input! only 1,2,3,4,5 or 6!')        continue
     

 代码都很简单，不做过多解释，重在理解class的概念