Unfollow Twitter NonFollowers bulk [python]

unfollow_nonfollowers.py

def unfollow():
    api = setup_api(consumer_key, consumer_secret, access_key, access_secret)
    i = 0
    while True:
        try:
            for page in Cursor(api.friends).pages():
                print 'page:', i
                f = open('out.txt','a')
                f.write(str(datetime.now()) + ' Page ' + str(i) + '\n')
                f.close()
                i += 1
                for friend in page:
                    while True:
                        try:
                            flag_unfollow = need_unfollow(api,friend)
                            if flag_unfollow:
                                while True:
                                    try:
                                        unfollow(api, friend)
                                        print 'Success unfollow', friend.screen_name
                                        f = open('out.txt','a')
                                        f.write(str(datetime.now()) + ' Success unfollow ' + friend.screen_name + '\n')
                                        f.close()
                                        break
                                    except Exception, e:
                                        print 'Error unfollow.. Time out 60 s', e
                                        f = open('out.txt','a')
                                        f.write(str(datetime.now()) + ' Error unfollow.. Time out 60 s' + str(e) + '\n')
                                        f.close()
                                        time.sleep(60)
                                        continue
                        except TweepError, e:
                            print 'Tweep Error need_unfollow.', e, 'Try again'
                            time.sleep(60)
                            continue
                        print 'Keep following', friend.screen_name
                        f = open('out.txt','a')
                        f.write(str(datetime.now()) + ' Keep Following ' + friend.screen_name + '\n')
                        f.close()
                        break
                print 'Slepping (for page)...'
                f = open('out.txt','a')
                f.write(str(datetime.now()) + ' Slepping (for page) ' + '\n')
                f.close()
                time.sleep(60)
        except TweepError, e:
            print '', e
            continue