python 创建多个线程并启动

th_num = conf["crawl_threads"]
self._thread_list = []

self._thread_states = [None,] * th_num
for tid in range(th_num):
th = threading.Thread(target=self.crawl_process, args=(tid,) )
self._thread_list.append(th)
th.start()

if self._thread_handle != None:
raise ValueError, "Loader has already started"
self._thread_handle = threading.Thread(target=self._loop_scan, args=())

self._scan_flag = True
self._thread_handle.start()