〖Demo〗-- 模拟登录

【模拟登录】

1. 用户输入帐号密码进行登陆
2. 用户信息保存在文件内
3. 用户密码输入错误三次后锁定用户

　　方法一 （分别输入姓名和密码）

#账号和密码
name = 'nikita'
password = '123'
count = 0
#读取黑名单
f = open('black_list.txt','r')
black = f.read()
f.close()
ls = []
#三次登录信息
T = True
while T:
    name1 = input('Please enter name:')
    #检查name1是否在black_list

    if name1 in black:
        print ('Sorry, you cannt login')
        break
    #不在black_list
    else:
        password1 = input("Please enter password:")
        if name == name1 and password == password1:
            print ('Welcome!')
            break

        else:
            print ('Your name and password are wrong')
            ls.append(name1)
            x = ls.count(name1) #输入的名字放入list里，当相同名字输入三次，锁定账号
            if x>=3:
                T = False
                print('Your account is locked.')
                f = open('black_list.txt','a')
                f.write(name1 + '
')
                f.close()
                break

方法二（先输入名字，在输入多次密码）

#账号和密码
name = 'nikita'
password = '123'
count = 0
#读取黑名单
f = open('black_list.txt','r')
black = f.read()
f.close()
#三次登录信息
name1 = input('Please enter name:')
#检查name1是否在black_list
if name1 in black:
    print ('Sorry, you cannt login')
#不在black_list
else:
    for i in range(3):
        password1 = input("Please enter password:")
        if name == name1 and password == password1:
            print ('Welcome!')

        else:
            print ('Your password is wrong')
            count+=1
#登录三次锁定账号
        if count == 3:
            print ('Your account is locked.')
            f = open('black_list.txt','a')
            f.write(name1+'
')
            f.close()