[Python/MangoDb/MangoEngine] 模拟数据库/增/删/改/查

最近学习了MangoDB 和 面向对象的MangoEngine 感觉很好用，况且利用python来调用将数据写入也很简单，代码如下：

#!/usr/bin/env python# -*- coding:utf-8 -*-from mongoengine import *import pymongoimport sysimport timeconnect('ceshi')class People(Document): #这个类集成 mongoengine 的Document的类    ID   = StringField(required=True)    name = StringField(required=True)    age  = StringField(required=True)    salary = StringField(required=True)class Database(object):    def __init__(self):        self.HELP = '''                    创建:insert id=1,name=a,age=18,saraly=5000                    查询所有:show all                    查询指定:select id=123                     修改:update id=1,name=hi                    删除:delete id=1                    帮助:help,man                    退出:exit,quit                    '''        print('''                                  Welcome To Small Database information management system''')        print('''                ____________                ||||||||||||=========================================                ||||||||||||=========================================                ||||||||||||                        ******************************            Successful Connection!!            ****************************''' )                 self.key = {}        self.run()    def run(self):        while True:            try:                cmd = str(raw_input('Mongodb: '))                cmd = cmd.strip()                if cmd == '':                    pass                elif (cmd == 'exit') or (cmd == 'quit'):                    print('Bey')                    sys.exit(1)                 elif (cmd == 'help') or (cmd == 'man'):                    print(self.HELP)                elif (cmd.startswith('insert')) and (len(cmd.split(',')) == 4):                    cmd = cmd.replace('insert','').lstrip()                    if  People.objects(ID=cmd.split(',',1)[0][3:]).count() == 0:                        self.key['id'] = cmd.split(',',1)[0][3:]                        self.key['name'] = cmd.split(',',4)[1][5:]                        self.key['age'] = cmd.split(',',4)[2][4:]                        self.key['salary'] = cmd.split(',',4)[3][7:]                        self.Add()                    else:                        print('Student ID has been repeated and cannot continue to add updates')                elif (cmd.startswith('update')):                    cmd = cmd.replace('update','').lstrip()                    if People.objects(ID=cmd.split(',')[0][3:]).count() != 0:                        self.Update(cmd.split(',')[0][3:],cmd.split(',')[1:])                    else:                        print('There is no ID number you want to modify')                elif (cmd.startswith('delete')) and (len(cmd.split()) == 2):                    if People.objects(ID=cmd.split('=')[1]):                        self.Delete(cmd.split('=')[1])                    else:                        print('Student number does not exist!')                elif (cmd.startswith('show')) and (len(cmd.split()) == 2):                    self.Showall()                elif (cmd.startswith('select')) and (len(cmd.split()) == 2):                    if People.objects(ID=cmd.split('=')[1]):                        self.Select(cmd.split('=')[1])                    else:                        print('Student number does not exist!')                else:                    print('syntax error')            except KeyboardInterrupt:                print('\nbye')                sys.exit(0)    def Add(self):        value = People(ID = self.key['id'],name=self.key['name'],age=self.key['age'],salary=self.key['salary'])        if value:            value.save()             print('  Successful!!  ')        else:            print('faild')    def Select(self,value):        dlist = People.objects.all()        dlist = People.objects(ID=value)        for each in dlist:            print('ID号:{}\t姓名:{}\t年龄:{}\t收入:{}\t'.format(each.ID,each.name,each.age,each.salary))    def Showall(self):        for each in People.objects:            print('ID号:{}\t姓名:{}\t年龄:{}\t收入:{}\t'.format(each.ID,each.name,each.age,each.salary))    def Delete(self,value):        idlist = People.objects(ID=value)        if  idlist.delete():            print('Successful!!!')        else:            print('Fiald')    def Update(self,Id,value):        modify = People.objects(ID=Id).first()          for i in range(len(value)):            if value[i][:value[i].index('=')] == 'id':                modify.ID = value[i][value[i].index('=')+1:]             elif value[i][:value[i].index('=')] == 'name':                modify.name = value[i][value[i].index('=')+1:]            elif value[i][:value[i].index('=')] == 'age':                modify.age = value[i][value[i].index('=')+1:]            elif value[i][:value[i].index('=')] == 'salary':                modify.salary = value[i][value[i].index('=')+1:]        print('Update Successful!!!')        modify.save()if __name__ == '__main__':    MyMongoDB = Database()