Python实现用户管理系统：核心编程第七章练习题详解

#-*- coding:utf-8 -*- 
#2017.7.17
 
import re 
import pickle 
import base64,hashlib 
from datetime import datetime 
 
def Initialization(file_name): 
 '''''程序初始化，创建user.ini和time.ini文件''' 
 dict_test={'admin':'db69fc039dcbd2962cb4d28f5891aae1'} #创建超级管理员，默认密码为admin 
 f = file(file_name,'a+') #以追加的方式打开文件，避免文件被修改 
 if len(f.readlines()) ==0: #判断程序是否为空，只在第一次运行的时候初始化 
  if file_name=='user.ini': 
   pickle.dump(dict_test, f, True) 
  else: 
   pickle.dump({},f, True) 
 f.close() 
 
def encodepass(passwd): 
 '''''采用base64和md5双层加密，破解可能几乎为0''' 
 m = hashlib.md5() 
 pwd = base64.b64encode(passwd) 
 m.update(pwd) 
 return m.hexdigest() 
 
def time_order(user): 
 '''''记录用户登陆时间，结果保存在time.ini文件中''' 
 ft = file('time.ini','r') 
 dbt = pickle.load(ft) 
 if user not in dbt: 
  dbt.setdefault(user,datetime.today()) 
 else: 
  time_value = dbt[user] 
  t = datetime.today()-time_value 
  try: 
   if t.hour<=4: 
    print 'You already logged in at:<last_login_timestamp>' 
  except: 
   print 'You already logged in at:<last_login_timestamp>' 
  dbt[user] = datetime.today() 
 ft = file('time.ini','w') 
 pickle.dump(dbt, ft, True) 
 ft.close() 
   
 
def newuser(db): 
 '''''用户创建程序，由olduser调用''' 
 while True: 
  name = raw_input('Please input the username:') 
  if re.match(r'\w', name): #采用正则表达式检测用户名是否合法 
   pass 
  else: 
   print 'Username should be made of A~Z、a~z、0~9、_' 
   continue 
  for valuename in db.keys(): 
   if name.lower() == valuename.lower(): 
    break 
  else: 
   break 
 passwd = raw_input('Please input the password:') 
 db[name] = encodepass(passwd) 
  
def olduser(db): 
 '''''用户登陆程序''' 
 name = raw_input('Login:') 
 if name in db: 
  pwd = raw_input('passwd:') 
  passwd = db.get(name) 
  if passwd == encodepass(pwd): 
   print 'Welcome back!',name 
   time_order(name) 
  else: 
   print 'Login incorrent!' 
 else: 
  YN = raw_input('Do you want to instead a new user? Yes or No:') 
  if YN.lower()=='yes': 
   newuser(db) 
 print '\n', 
   
def deluser(db): 
 '''''删除一个用户，但必须以管理员的身份''' 
 print 'Please login as admin' #管理员的身份才能删除用户 
 name = raw_input('Login:') 
 pwd = raw_input('passwd:') 
 passwd = db.get(name) 
 if passwd == encodepass(pwd) and name=='admin': 
  user = raw_input('Please input a user name:') 
  if user != 'admin': 
   if db.pop(user): 
    print 'Delete Current!' 
  else: 
   print 'Con not delete admin!' 
 else: 
  print 'Wrong passwprd' 
  
def checkuser(db): 
 '''''查看所有用户，但必须以管理员的身份''' 
 print 'Please login as admin' #管理员的身份才能查看所有用户 
 name = raw_input('Login:') 
 pwd = raw_input('passwd:') 
 passwd = db.get(name) 
 if passwd == encodepass(pwd) and name == 'admin': 
  for key in db: 
   print 'username: %10s ====> password: %10s' % (key,db[key]) 
 else: 
  print 'You can not check all users!' 
 
def resetuser(db): 
 '''''修改密码，但必须正确的输入老密码''' 
 name = raw_input('Please input the username：') 
 passwd = raw_input('Please input old password：') 
 if db[name] == encodepass(passwd): 
  passwd = raw_input('Please input new password：') 
  db[name] = encodepass(passwd) 
 else: 
  print 'Wrong password!' 
 
def showmenu(): 
 '''''程序运行的主函数''' 
 fu = file('user.ini','r') 
 db = pickle.load(fu) 
 prompt = '''''(L)ogin Now
(Q)uit
(D)elet User
(C)heck All User
(R)eset Password
Enter choice:''' 
  
 done = False 
 while not done: 
  chosen = False 
  while not chosen: 
   try: 
    choice = raw_input(prompt).split()[0].lower() 
   except (EOFError,KeyboardInterrupt): 
    choice = 'q' 
   print '\nYou picked:[%s]' % choice 
   if choice not in 'lqdcr': 
    print 'invalid option,try again' 
   else: 
    chosen = True 
      
  if choice == 'q':done = True 
  if choice == 'l':olduser(db) 
  if choice == 'd':deluser(db) 
  if choice == 'c':checkuser(db) 
  if choice == 'r':resetuser(db) 
   
 fu = file('user.ini','w') 
 pickle.dump(db,fu,True) 
 fu.close() 
   
   
if __name__ == '__main__': 
 '''''系统有一个用户名为admin 密码为admin的超级用户,请立即修改密码！''' 
 print 'Welcome to User Information Management System!' 
 Initialization('user.ini') 
 Initialization('time.ini') 
 showmenu()