题目需求：

1.输入用户名密码

2.认证成功后显示欢迎信息

3.输错三次后锁定

#读取注册用户的信息，用户名，密码，输错次数，写入字典中

user={}

with open("DB1",encoding="utf8") as f:

for line in f:

username_list=line.strip().split("|") #username_list--->['egon', '123', '2']

user[username_list[0]]={"name":username_list[0],

"pwd":username_list[1],

"times":username_list[2]}

# print(user) #-->{'egon': {'name': 'egon', 'pwd': '123', 'times': '2'}, 'xuyaping': {'name': 'xuyaping', 'pwd': '123', 'times': '0'}, 'xyy': {'name': 'xyy', 'pwd': '123', 'times': '1'}}

#读取黑名单用户，将黑名单用户加入列表中

with open("black_lockname",encoding="utf8") as f1:

black_list=[]

for line in f1:

black_list.append(line.strip())

# print(black_list)

while True:

username = input("please input your username:").strip()

passwd = input("please input your passwd:").strip()

#用户在黑名单中

if username in black_list:

print("该用户为黑名单用户，请滚")

break

# 用户为注册用户

elif username in user:

user[username]["times"]=int(user[username]["times"])

if user[username]["times"]<3 and passwd==user[username]["pwd"]:

print("登录成功")

user[username]["times"]=0

#将修改后的信息重新写入DB1中

with open("DB1","w",encoding="utf8") as f3:

for i in user:

f3.write(i + "|" + user[i]["pwd"] + "|" + str(user[i]["times"]) + "\n")

break

else:

user[username]["times"]+=1

print("登录错误")

# 将修改后的信息重新写入DB1中

with open("DB1", "w", encoding="utf8") as f3:

for i in user:

f3.write(i + "|" + user[i]["pwd"] + "|" + str(user[i]["times"]) + "\n")

if user[username]["times"]==3:

black_list.append(username)

print("账户被锁定")

# 将修改后的信息重新写入black_lockname中

with open("black_lockname","w",encoding="utf8") as f4:

for j in black_list:

f4.write(j+ "\n")

break

#用户不是注册用户

else:

print("该用户没有注册")

break

xuyaping|123|0

egon|123|1xuyuanyuan|123|2

DB1

alex

black_lockname