从函数内的列表返回非重复的随机结果

Question

I am writing a Python program that responds to request and vocalizes a response back to the user. Below is a sample of two functions. How can I do this without using a global variable and still get back a non-repeating, random response?

# stores prior response

website_result = 'first_response.wav'

def launch_website():

    # if service is offline return with default msg otherwise launch service

    if is_connected() == 'FALSE':
       arg = 'this_service_is_offline.wav'
       return arg
    else:
       site = 'http://www.somesite.com'
       launch_it(site)

    return launch_website_response()

def launch_website_response():

    # using the global variable inside function

    global website_result

    # possible responses

    RESPONSES = ['first_response.wav', 'second_response.wav', 'third_response.wav']

    # ensures a non-repeating response

    tmp = random.choice(RESPONSES)
    while website_result == tmp:
       tmp =  random.choice(RESPONSES)

    website_result = tmp
    return website_result

Answer 1

Your website_result variable indicates that you to have some sort of persistent state. Maybe you could consider storing it in a text file and access it everytime you need it and change it afterward (this works if you don't have to do too many calls to it, otherwise you will get in I/O limitations).

I don't know about the specifics of your application, but it might happen that you could also make your two functions take website_result as an argument as suggested by @JGut.