用Python写一段用户登录的程序代码

如下所示：

#!/usr/bin/env python
#coding: utf8
import getpass
db = {}
def newUser():
username = raw_input('username: ')
if username in db:
#添加打印颜色
print "\033[32;1m％s already exists![0m" ％ username
else:
#屏幕不显示密码，调用getpass.getpass()
password = getpass.getpass()
db[username] = password #字典k-v赋值
def oldUser():
username = raw_input('username: ')
password = getpass.getpass()
if username in db:
if db.get(username) == password:#判断输入的用户名和密码是否和字典的k-v匹配
 print '\033[32;1mlogin successful!\033[0m'
else:
 print '\033[32;1mpassword not match username\033[0m'
else:
print '\033[32;1musername does not exist\033[0m'
CMDs = {'n':newUser,'o':oldUser}
def showMenu():
prompt = """(N)ew user
(O)ld user
(Q)uit
input your choice: """
while True:
try:#捕获ctrl+c ctrl+d的异常
 choice = raw_input(prompt).strip().lower()[0]
except (KeyboardInterrupt, EOFError):
 choice = 'q'
if choice not in 'noq':
 continue
if choice == 'q':
 break
CMDs[choice]()#这种方法相当于shell和c里面的case，很实用
if __name__ == '__main__':
showMenu()

来源：https://blog.csdn.net/huangyingleo/article/details/54232870