age = 25
a = 3
for i in range(1,4):
    print("You have %d changes!" % a)
    guess = int(input("please input your guess:"))
    if guess > age:
        print("Try smaller....")
    elif guess < age:
        print("Try bigger....")
    else:
        print("You guess it!")
        break
    a = a - 1

age = 25
continue1 = "y"
time = 1
time1 = 0
while True :
    if continue1 == "n":
        break
    elif continue1 == "y":
        if time % 3 !=0:
            guess = int(input("please input your guess:"))
            if guess > age:
                print("Try smaller....")
            elif guess < age:
                print("Try bigger....")
               else:
                print("You guess it!")
                break
            time = time1 + 1
            time1 = time1 + 1
    else:
        while 1:
            con = input("Do you want continue? [y/n]:")
            if con == "y":
                continue1 = "y"
                time = 1
                time1 = 0
                break
            elif con == "n":
                continue1 = "n"
                break
            else:
                print("Input error,please input the new![y or n]")

输入用户密码
认证成功显示欢迎信息
输错三次后锁定




def black_use(name):  #从黑名单中匹配用户名。
    black = open("blacklist.txt", "r+")
    b1 = black.readline().strip()
    while b1 != "":
        if name == b1:
            print("The name is disabled!")
            global a,used1,used
            a = a - 1
            used1 = False
            used = None
            black.seek(0,0)
            break
        else:
            b1 = black.readline().strip()

def  enter(name,passd): #从可用用户单中匹配用户名和密码。
    global use1,used
    use = open("used.txt", "r")
    name_r = use.readline().strip()
    passd_r = use.readline().strip()
    while name_r != "":
        if name == name_r and passd == passd_r:
            used = True
            break
        else:
            name_r = use.readline().strip()
            passd_r = use.readline().strip()

a = 3
for i in range(1,4):
    used1 = True  #True表示没有在黑名单中找到用户。False表示在黑名单中找到用户。
    used = False  #True表示用户登录成功，False表示登录失败，用户名和密码对不上。
    print("You have %s chances!" % a)
    name = input("Please input your name:")
    passd = input("Please input your password:")
    black_use(name)
    if used1 == True :
        enter(name,passd)
    if used == False:
        print("The name or password is wrong!")
        a = a - 1
    elif used == True:
    print("Welcome,%s" % name)
    break
else:
    pass
if a ==0 and used1 == False:  #如果次数用完，并且用户名不在黑名单中，则加入到黑名单中。
    black = open("blacklist.txt", "a+")
    black.write("n%s" % name)
    black.close()