134さんのpythonをctrl+cで中断すると、次のようなエラー出ますね
^CException in thread Thread-1 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
File "/usr/lib/python2.7/threading.py", line 759, in run
File "hoge.py", line 101, in tick
File "hoge.py", line 29, in authenticate
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'randint'
