作业需求：
1. 员工信息表程序，实现增删改查操作：
2. 可进行模糊查询，语法至少支持下面3种:
select name,age from staff_table where age > 22
select * from staff_table where dept = "IT"
select * from staff_table where enroll_date like "2013"
查到的信息，打印后，最后面还要显示查到的条数
3. 可创建新员工纪录，以phone做唯一键，staff_id需自增
4. 可删除指定员工信息纪录，输入员工id，即可删除
5. 可修改员工信息，语法如下:
UPDATE staff_table SET dept="Market" where dept = "IT"
6. 注意：以上需求，要充分使用函数，请尽你的最大限度来减少重复代码
思路解析：
1. 将原始员工信息记录到文件
2. 读取文件并添加到列表，进行添加删除更新操作，并写入到文件中
程序核心代码:
peopledb
1,Jack Wang,30,43304320533,INS,2015-05-03 2,Alex Li,22,23651054608,IT,2013-04-01
员工信息表.py
#!/usr/bin/env python # -*- coding:utf-8 -*- # Author: Colin Yao """python 员工信息表操作""" import sys import os def select1(): ''' 查看文件函数 :return: ''' with open('peopledb', 'r', encoding='utf-8') as f: line = f.readlines() for i in line: print(i) def select(): ''' 查询函数 :return: ''' msg = ''' 请输入或复制查询命令例如： 1. select name,age from staff_table where age > 22 2. select * from staff_table where dept = "IT" 3. select * from staff_table where enroll_date like "2013" ''' print(msg) user_choice_input = input(">>>:") user_choice_input1 = user_choice_input.split(' ') if user_choice_input == 'select name,age from staff_table where age > %s' % (user_choice_input1[7]): with open('peopledb', 'r+', encoding='utf-8') as f: list1 = [] count = 0 for line in f: i = line.strip().split(',') if i[2] > user_choice_input1[7]: list1.append(i) for s in list1: count = count + 1 for j in list1: print(j) print('满足条件的个数为>>:%s' % (count)) elif user_choice_input == ('select * from staff_table where dept = %s' % (user_choice_input1[7])): with open('peopledb', 'r+', encoding='utf-8') as f: list2 = [] count = 0 for line in f: i1 = line.strip().split(',') if i1[4] == eval(user_choice_input1[7]): list2.append(i1) for s1 in list2: count = count + 1 # print(list1) for j1 in list2: print(j1) print('满足条件的个数为>>:%s' % (count)) elif user_choice_input == ('select * from staff_table where enroll_date like %s' % (user_choice_input1[7])): with open('peopledb', 'r+', encoding='utf-8') as f: list3 = [] list4 = [] count = 0 for line in f: i = line.strip().split(',') list3.append(i) for j in list3: m = j[5].split('-') if m[0] == eval(user_choice_input1[7]): list4.append(j) for s in list4: count = count + 1 if count < 1: print("没有找到类似的条目:") pass else: pass for j in list4: print(j) print('满足条件的条数为>>:%s' % (count)) return () def alter(): ''' 添加函数 :return: ''' msg = ''' 1)添加命令如下：Jack Wang,30,13304320533,HR,2015-05-03 ''' print(msg) user_choice_input = input("请输入命令>>>:") user_choice_input1 = user_choice_input.split(',') with open('peopledb', 'r+', encoding='utf-8') as f: list = [] for line in f: s2 = line.strip().split(',') m = s2[3] list.append(m) if user_choice_input1[2] in list: print('这条记录已经存在') main() else: my_index = str(len(list) + 1) user_choice_input1.insert(0, my_index) user_choice_input1 = ','.join(user_choice_input1) f.write(' ') f.write(user_choice_input1) f.close() print("记录添加完成", ' ') select1() return () def delect(): ''' 删除函数 :return: ''' print("请输入删除命令例如: 输入用户ID 既可以从staff_table里删除") msg = ''' 1)按1 删除、直接删除ID即可 2)按2或者q退出 3)按任意返回上一层 ''' print(msg) user_choice_input = input("请输入命令>>>: ") if user_choice_input == '1': print("现有的用户为:") select1() print(' ') user_choice_input1 = input("请输入需要删除的用户ID:") user_choice_input2 = user_choice_input1[0] f = open('peopledb', 'r+', encoding='utf-8') f1 = open('new_peopledb', 'w+', encoding='utf-8') for line in f: i = line.strip().split(',') i1 = i[0] if user_choice_input2 != i1: i = ','.join(i) f1.write(i) f1.write(' ') else: continue f.close() f1.close() os.remove('peopledb') os.rename('new_peopledb', 'peopledb') print(' ') select1() elif user_choice_input == '2' or 'q': sys.exit() return () def update(): ''' 更新函数 :return: ''' msg = ''' 1)这里第一个等号按照没有空格的格式划分 2)命令范例:UPDATE staff_table SET dept="INS" where dept = "HR" ''' print(msg) user_choice_input = input("请输入命令>>>:") user_choice_input1 = user_choice_input.split(' ') dept = user_choice_input1[3].split('=') dept_new = dept[1] dept_old = user_choice_input1[7] if user_choice_input == ('UPDATE staff_table SET dept=%s where dept = %s' % (dept_new, dept_old)): dept_new1 = eval(dept_new) dept_old1 = eval(dept_old) f = open('peopledb', 'r+', encoding='utf-8') f1 = open('new_peopledb', 'w+', encoding='utf-8') for line in f: i = line.strip().split(',') dept_change = i[4] if dept_change == dept_old1: i[4] = eval(dept_new) i = ','.join(i) f1.write(i) f1.write(' ') f.close() f1.close() os.remove('peopledb') os.rename('new_peopledb', 'peopledb') print(' ') select1() pass return () def main(): ''' 交互程序 :return: ''' print("员工信息表操作作业练习") msg = ''' 1）查询 2）添加 3）删除 4）更新 5) 退出 ''' exit_flag = False while not exit_flag: print(msg) user_choice = input("请选择>>:") if user_choice == '1': select() elif user_choice == '2': alter() elif user_choice == '3': delect() elif user_choice == '4': update() elif user_choice == '5' or 'q': sys.exit() else: print("您的选择有误、请重新输入") main()