import threading

def prt_hello() :
  while 1 :
    print 'hello'

if __name__ == '__main__' :
  t = threading.Thread(target=prt_hello)
  t.setDaemon(True)
  t.start()

import threading
import time
import os
 
# 原本需要用来启动的无线循环的函数
def print_thread():
  pid = os.getpid()
  counts = 0
  while True:
    print(f'threading pid: {pid} ran: {counts:04d} s')
    counts += 1
    time.sleep(1)
 
# 把函数放到改写到类的run方法中，便可以通过调用类方法，实现线程的终止
class StoppableThread(threading.Thread):
 
  def __init__(self, daemon=None):
    super(StoppableThread, self).__init__(daemon=daemon)
    self.__is_running = True
    self.daemon = daemon
 
  def terminate(self):
    self.__is_running = False
 
  def run(self):
    pid = os.getpid()
    counts = 0
    while self.__is_running:
      print(f'threading running: {pid} ran: {counts:04d} s')
      counts += 1
      time.sleep(1)
 
 
def call_thread():
  thread = StoppableThread()
  thread.daemon = True
  thread.start()
 
  pid = os.getpid()
  counts = 0
  for i in range(5):
    print(f'0 call threading pid: {pid} ran: {counts:04d} s')
    counts += 2
    time.sleep(2)
  # 主动把线程退出
  thread.terminate()
 
 
if __name__ == '__main__':
  call_thread()
  print(f'==========call_thread finish===========')
  counts = 0
  for i in range(5):
    counts += 1
    time.sleep(1)
    print(f'main thread:{counts:04d} s')