我可以改进当前的Python代码吗？

Question

我刚开始学习Python，决定尝试这个来自Python Wiki的小项目：

写一个密码猜测程序，记录用户输入错误密码的次数。如果超过3次，就打印“你已被拒绝访问。”并结束程序。如果密码正确，就打印“你已成功登录。”并结束程序。

这是我的代码。它能正常工作，但我觉得用这些循环中断和嵌套的if语句写起来不太舒服。

# Password Guessing Program
# Python 2.7

count = 0

while count < 3:
    password = raw_input('Please enter a password: ')
    if password != 'SecretPassword':
        count = count + 1;
        print 'You have entered invalid password %i times.' % (count)
        if count == 3:
            print 'Access Denied'
            break
    else:
        print 'Access Granted'
        break

Answer 1

granted = False # default condition should be the least dangerous
for count in range(3):
    password = raw_input('Please enter a password: ')
    if password == 'SecretPassword': # no need to test for wrong answer
        granted = True
        break
    print 'You have entered invalid password %i times.' % (count+1) # else

if granted:
    print 'Access Granted'
else:
    print 'Access Denied'

当然可以！请把你想要翻译的内容发给我，我会帮你用简单易懂的语言解释清楚。

Answer 2

我并不反对使用循环和条件判断这种“命令式”的写法，但我建议把你的“业务逻辑”和“展示部分”分开。

count = 0

# Business logic
# The correct password and the maximum number of tries is placed here
DENIED, VALID, INVALID = range(3)
def verifyPassword(userPassword):
    global count
    count += 1

    if count > 3:
        return DENIED
    elif password == 'SecretPassword':
        return VALID

    return INVALID

# Presentation
# Here you do the IO with the user
check = INVALID
while (check == INVALID):
    password = raw_input('Please enter a password: ')
    check = verifyPassword(password)

    if check == INVALID:
        print 'You have entered invalid password %i times.' % (count)
    elif check == VALID:
        print 'Access Granted'
    else # check == DENIED
        print 'Access Denied'

Answer 3

你可以用下面这个函数来替代你的 while 循环：

def login():
    for i in range(3):
        password = raw_input('Please enter a password: ')
        if password != 'SecretPassword':
            print 'You have entered invalid password {0} times.'.format(i + 1)
        else:
            print 'Access Granted'
            return True
    print 'Access Denied'
    return False

你也可以考虑使用 getpass 这个模块。