Get access token facebook-sdk

I'm trying to figure out, how to log in to facebook account and get access token so I can post into my groups.

To create a GraphAPI instance, I need to check access_token which I need and put it into the code.

I'm curious whether is it possible to use username and password to get the access_token automatically so the program can be used by more users.

oauth_access_token = 'ACCESS TOKEN WHICH I HAVE TO GET FROM http://ift.tt/1baC4nV'

def post_to_1_group(user,password,post):

    graph = facebook.GraphAPI(oauth_access_token)
    groups = graph.get_object("me/groups")
    group_id = groups['data'][1]['id'] # select the first group I'm in

    graph.put_object(group_id, "feed", message=post)

This code works but it doesn't use user and password arguments. I have to check my access_token everytime I want to run the program.

Is it possible?