正则表达式之实战--员工信息表

Posted 2020-10-12 七度王爵

import re
import json
‘‘‘
员工表只设置了staff_id、staff_name、age、phone字段
其中phone是唯一的
1、查询支持select * from staff_table where age < 100；select staff_name,age from staff_table where staff_name = "diaochan";

select staff_name,age from staff_table where age > 10;select * from staff_table where staff_name like "xiang";

2、修改支持update staff_table set staff_name = "zhangsan" where staff_name = "xiangyu"；(只写了修改姓名)
3、因为切割的原因 age > 22 必须间隔空格
‘‘‘
select = re.compile(r‘(select .+ from staff_table where .+\s*\=?\>?\<?(like)?\s*.+)‘)   #sql的正则，判断查询sql是否符合规则
modify = re.compile(r‘update staff_table set .+\s*=\s*\"*.+\"* where .+\s*=\s*\"*.+\"*‘,re.I)   #判断更新sql是否符合规则
seek = re.compile(r‘[^select]\s*(?P<key>\*{1})|[^select]\s*(?P<key1>(\w+\,{1}\w+){1})‘)         #匹配select后的内容 * 或者 字段
sn = re.compile(r‘(\w+\s+\>+\s+\"?\‘?\w+\"?\‘?)|(\w+\s+\=+\s+\"?\‘?\w+\"?\‘?)|(\w+\s+\<+\s+\"?\‘?\w+\"?\‘?)|(\w+\s*(like)+\s*\"?\‘?\w+\"?\‘?)‘)   #匹配<、>、=、like的前后内容 name like "zhang"
up = re.compile(r‘(?P<sn>(\w+\s*\=\s*\w+))‘)   #匹配=的规则
rm = re.compile(r‘[^"]\w*‘)  #脱双引号的规则

def re_sql(sql):
    ‘‘‘
    该函数实现sql语句的正则判断
    :param sql: 
    :return: 
    ‘‘‘
    tf = select.search(sql)
    tf1 = modify.search(sql)
    if tf or tf1:
        return True
    else:
        return False

def find_staff(sql):
    ‘‘‘
    该函数实现了查询员工，支持select name,age from staff_table where age < 100   
    select  * from staff_table where name = "yuji"
    select  * from staff_table where name like xiang
    :param sql: 
    :return: 
    ‘‘‘
    staff = load_staff()           #文件中加载所有用户信息
    count = 0
    you_need = seek.search(sql).groupdict()
    if you_need["key"] != None:     #如果匹配到*
        you_sn = sn.search(sql).group()
        res = re.split(r‘\s‘,you_sn)
        for temp in res:
            if "like" in temp:  #如果匹配的是like
                for st in staff:
                    if rm.search(res[2]).group() in st[res[0]]:
                        print(st)
                        count += 1
            elif "=" in temp:   #如果匹配的是 =
                for st in staff:
                    if rm.search(res[2]).group() == st[res[0]]:
                        print(st)
                        count += 1
            elif ">" in temp:  #如果匹配的是 >
                for st in staff:
                    # if int(re.search(r‘[^\"?]\w+[^\"?]‘,res[2]).group()) > int(st[res[0]]):
                    if int(re.search(r‘[^\"?]\w*‘, res[2]).group()) < int(st[res[0]]):
                        print(st)
                        count += 1
            elif "<" in temp:  #如果匹配的是 <
                for st in staff:
                    if rm.search(res[2]).group() > st[res[0]]:
                        print(st)
                        count += 1
    elif you_need["key1"] != None:  #如果匹配的是字段 age、staff_name
        you_sn = sn.search(sql).group()
        res = re.split(r‘\s‘, you_sn)
        u_key = re.split(r‘\,‘ ,you_need["key1"])
        for temp in res:
            if "like" in temp:
                for st in staff:
                    if rm.search(res[2]).group() in st[res[0]]:
                        print(st[u_key[1]], st[u_key[0]])
                        count += 1
            elif "=" in temp:
                for st in staff:
                    if rm.search(res[2]).group() == st[res[0]]:
                        print(st[u_key[1]], st[u_key[0]])
                        count += 1
            elif ">" in temp:
                for st in staff:
                    if int(re.search(r‘[^\"?]\w*‘, res[2]).group()) > int(st[res[0]]):
                        print(st[u_key[1]], st[u_key[0]])
                        count += 1
            elif "<" in temp:
                for st in staff:
                    if rm.search(res[2]).group() < st[res[0]]:
                        print(st[u_key[1]],st[u_key[0]])
                        count += 1

    print("共查询出%d条数据"%count)     #打印查询出的条数

def add_staff():
    ‘‘‘
    该函数实现了添加员工，需要输入员工姓名，年龄，手机号码，其中手机号码是唯一，姓名输入英文，为了查询时like用
    :return: 
    ‘‘‘
    staff_list = []
    staff_dict = {}
    name = input("请输入员工姓名 >>>>")
    age = input("请输入员工年龄 >>>>")
    phone = input("请输入员工手机号码 >>>>")
    staff = load_staff()
    for i in range(len(staff)):
        if staff[i]["phone"] == phone:                  #判断号码是否重复
            print("手机号码不能重复")
            exit()
        staff_id = staff[i]["staff_id"]
        staff_list.append(staff[i])
    staff_id = str(int(staff_id) + 1)               #staff_id 自增加
    staff_dict["staff_id"] = staff_id
    staff_dict["staff_name"] = name
    staff_dict["age"] = age
    staff_dict["phone"] = phone
    staff_list.append(staff_dict)                   #json序列化的时候只能一行，所以用列表保存信息
    dump_staff(staff_list)
    print("添加成功")

def remove_staff(id):
    ‘‘‘
    该函数实现了删除员工，使用员工id
    :param id: 
    :return: 
    ‘‘‘
    staff_list = []
    staff = load_staff()
    flag = 0
    for i in range(len(staff)):
        if staff[i]["staff_id"] == id:          #如果找到输入的id则跳出此次循环，不加入列表
            flag = 1
            continue
        staff_list.append(staff[i])
    if flag == 0:                               #如果没有匹配到输出没有该id的员工
        print("没有id：%s的员工"%id)
    else:
        dump_staff(staff_list)                  #否则json保存信息

def modify_staff(sql):
    ‘‘‘
    该函数实现了修改名字 update staff_table set staff_name = "xiangyu" where staff_name="jack"
    :param sql: 
    :return: 
    ‘‘‘
    staff_list = []
    staff = load_staff()
    s = re.findall(r‘\w+\s*\=\s*\"?\w+\"?‘,sql)
    if s != None:
        ps = re.split(r‘\s*\=?\s*‘,s[0])
        rs = re.split(r‘\s*\=?\s*‘,s[1])
        for m in range(len(staff)):
            if staff[m][ps[0]] == rm.search(rs[1]).group():
                staff[m][ps[0]] = rm.search(ps[1]).group()
            staff_list.append(staff[m])
    dump_staff(staff_list)
    print("员工信息修改成功")

def dump_staff(s):
    with open("员工信息表","w",encoding=‘utf-8‘) as f:
        json.dump(s,f)

def load_staff():
    with open("员工信息表",encoding=‘utf-8‘) as f:
        return json.load(f)

def print_info():
    info = ‘‘‘
**********欢迎登陆员工信息中心***********  
        1.查询员工
        2.新增员工
        3.修改员工
        4.删除员工
        5.退出
    ‘‘‘
    print(info)

def main():
    print_info()
    choise = input("请输入操作 >>>>")
    if choise == "1":
        sql = input("请输入对应的sql >>>")
        result = re_sql(sql)
        if result:
            find_staff(sql)

        else:
            print("sql语法错误")
    elif choise == "2":
        add_staff()
    elif choise == "3":
        sql = input("请输入对应的sql >>>")
        result = re_sql(sql)
        if result:
            modify_staff(sql)
        else:
            print("sql语法错误")
    elif choise == "4":
        id = input("请输入需要删除的员工id >>>")
        remove_staff(id)
    elif choise == "5":
        exit("退出系统")
    else:
        print("输入有误，请重新输入")



while True:
    main()