员工信息代码之---增删改查（装饰器、生成器、文件操作）

import os
dic = {'id':0,'name':1,'age':2,'phone':3,'job':4}
user_dic = {'name':'admin','passwd':'123456'}


#读取文件---将文件中的内容整理到内存中
def get_line(filename):
    with open(filename,mode='r+',encoding='utf-8') as f:
        for line in f:
            line = line.strip()
            line_lst = line.split(',')
            yield line_lst
# #
# # #条件筛选
def condition_filter(condition):
    # print(condition)
    condition=condition.strip()
    if '>' in condition:
        col,val = condition.split('>')
        g = get_line('userinfo')
        for line_lst_1 in g:
            if int(line_lst_1[dic[col]]) > int(val):
                yield line_lst_1
    elif '<' in condition:
        col,val = condition.split('<')
        g = get_line('userinfo')
        for line_lst_1 in g :
            if int(line_lst_1[dic[col]]) < int(val):
                yield line_lst_1
    else:
        col,val = condition.split('=')
        g = get_line('userinfo')
        for line_lst_1 in g:
            if int(line_lst_1[dic[col]]) == int(val):
                yield line_lst_1
# # #展示符合条件的员工信息
def views(view_list,staff_g):
    if '*' in view_list:
        view_list = dic.keys()
        for staff_info in staff_g:
            for i in staff_info:
                print(i,end=' ')
            print(end='
')
        # print(view_list)
    for staff_info in staff_g:
        print(staff_info[dic[view_list[0]]],staff_info[dic[view_list[1]]])
#
# #
# # #接受用户输入的信息
# ret = input('select name,age where age=23')
ret = 'select name,job where age>22'
view,condition = ret.split('where')
view = view.replace('select','').strip()
view_list = view.split(',')
# print(view_list,condition)
# g = condition_filter(condition)     #此处3行代码已经放在最下面装饰器处统一调用
# views(view_list,g)


#
# #修改表中对应数据

def update():
    # up_data = input('请输入需要更新的数据，例如：set age=100 where name=Egon： ')
    up_data = 'set age=100 where name=Egon'
    if 'set' and 'where' in up_data:
        cont,condit = up_data.strip().split('where')
        print(cont,condit)
        cont = cont.split('set')
        cont = cont[1].strip()
        update_name,update_value = cont.split('=')
        print(update_name,update_value)
        names,value = condit.strip().split('=')
        print(names,value)
        with open('userinfo',encoding='utf-8') as f,open('userinfo.bak',mode='w+',encoding='utf-8') as f1:
            for line in f:
                line_list = line.strip().split(',')
                # print(line_list)
                if line_list[dic[names]] == value:
                    before_value = line_list[dic[update_name]]
                    line = line.replace(before_value,update_value)
                f1.write(line)
    os.remove('userinfo')
    os.rename('userinfo.bak','userinfo')

# update('userinfo')
# # #删除表中对应数据
def delete():
    # del_data = input('请输入要删除的ID，例如：delete * where id=：')
    del_data = 'delete * where id=2'
    if 'delete' and 'where' in del_data:
        delete_content,delete_cond = del_data.strip().split('where') #以where分割
        # print(delete_content,delete_cond)
        if delete_content.strip() and delete_cond.strip():   #判断delete_content和delete_cond是否为空，不为空执行下面程序
            name,value = delete_cond.strip().split('=')     #以‘=’分割
            print(name,value)
            with open('userinfo',mode='r',encoding='utf-8') as f:
                for line in f:
                    line_list = line.strip().split(',') #以逗号分割以列表形式展示
                    # print(line_list)  #打印循环的文件
                    if line_list[dic[name.strip()]] == value.strip():
                        line = line.replace(line,'')
                    with open('userinfo.bak', mode='a', encoding='utf-8') as f1:
                        f1.write(line)
            os.remove('userinfo')
            os.rename('userinfo.bak','userinfo')

#数据增加
# dic = {'id':0,'name':1,'age':2,'phone':3,'job':4}
def add():
    s = 'add children,26,15055555588,Student'
    add_user = s.strip().split('add')
    # print(add_user)
    user_str = ''
    for i in add_user:
        user_str += i
    user_str = user_str.strip()
    # print(user_str)
    with open('userinfo',mode='r',encoding='utf-8') as f:
        for line in f:
            line = line.strip()
            line_list = line.strip().split(',')
        user_id = int(line_list[0])
    with open('userinfo','a+',encoding='utf-8') as f1:
        f1.write('
'+str(user_id+1)+','+user_str)




#装饰器函数 ---验证用户登录
# def check():
#     print(1)
# def delete():
#     print(2)
# def add():
#     print(3)
# def update():
#     print(4)
def wrapper(func):                 #func=main
    def inner(*args,**kwargs):
        username = input('请输入您的用户名：')
        password = input('请输入您的密码：')
        if username.strip() ==user_dic['name'] and password.strip() ==user_dic['passwd']:
            print('登录成功',end='')
            ret = func(*args,**kwargs)
            return ret
        else:print('用户名或密码错误，请重新输入：')
    return inner
@wrapper                   #main=login(main)   main=inner
def login():
    msg = {'1':condition_filter,'2':delete,'3':add,'4':update}
    print('''
        1:查询
        2：删除
        3：添加
        4：更新
    ''')
    num = input('请选择要执行的操作').strip()
    if int(num) == 1:
        g = msg[num](condition)
        # g = condition_filter(condition)
        views(view_list, g)
    else:
        msg[num]()
login()