python学习第一课

Posted 2021-01-05 raypy

第一步，实现 输入账号密码，显示账号欢迎：

username = input("username :")
password = int(input("password :"))
print("welcome  ",username,"!!!!!!!!!")

第二步，判断账号密码是否正确：

userlist1=["a",123]
username = input("username :")
password = int(input("password :"))
if (username == userlist1[0]) & (password==userlist1[1]):
    print("welcome  ",username,"!!!!!!!!!")
else:print("erro")

第三步，利用表，判断账号是否存在，且密码正确：

dict = {‘a‘: 123, ‘b‘: 234};
username = str(input("username :"))
password = int(input("password :"))
if (dict.__contains__(username)) & (password == dict.get(username)):
    print("welcome  ", username, "!!!!!!!!!")
else:
    print("erro")

第四步，限制只能输入三次：

dict = {‘a‘: 123, ‘b‘: 234};
count=0
while count<3 :
    username = input("username :")
    password = int(input("password :"))
    if (dict.__contains__(username)) & (password == dict.get(username)):
        print("welcome  ",username,"!!!!!!!!!")
        break
    else:
        print("您已输入错误",count+1,"次，输入错误3次锁定")
        count += 1

第五步，限制同一账号，只能输入错误3次，超出退出程序：

dict = {‘a‘: 123, ‘b‘: 234};
count=0
errolist=[]
while count<3 :
    username = str(input("username :"))
    errolist.append(username)
    password = int(input("password :"))
    if ( dict.__contains__( username) ) & (password==dict.get(username)):
        print("welcome  ",username,"!!!!!!!!!")
        break
    else:
        print("您已输入错误",errolist.count(username),"次，输入错误3次锁定")
        count = errolist.count(username)

 第六步：限制同一账号，只能输入错误3次，限制所有错误5次，超出退出程序：

dict = {‘a‘: 123, ‘b‘: 234,‘c‘:456};
count=0
errolist=[]
blacklist=[]
while count<5 :
    username = str(input("username :"))
    errolist.append(username)
    password = int(input("password :"))
    if (blacklist.count(username)<3):
        if ( dict.__contains__( username) ) & (password==dict.get(username)):
            print("welcome  ",username,"!!!!!!!!!")
            break
        else:
            print("您已输入错误",errolist.count(username),"次，输入错误3次锁定")
            blacklist.append(username)
            count +=1
            print(count)
            if (count == 5) :
                print("您尝试错误5次，程序将退出")
                break
    else:print("您已输入错误3次锁定")