thread stop python

# Python program using
# traces to kill threads
  
import sys
import trace
import threading
import time
class thread_with_trace(threading.Thread):
  def __init__(self, *args, **keywords):
    threading.Thread.__init__(self, *args, **keywords)
    self.killed = False
  
  def start(self):
    self.__run_backup = self.run
    self.run = self.__run      
    threading.Thread.start(self)
  
  def __run(self):
    sys.settrace(self.globaltrace)
    self.__run_backup()
    self.run = self.__run_backup
  
  def globaltrace(self, frame, event, arg):
    if event == 'call':
      return self.localtrace
    else:
      return None
  
  def localtrace(self, frame, event, arg):
    if self.killed:
      if event == 'line':
        raise SystemExit()
    return self.localtrace
  
  def kill(self):
    self.killed = True
  
def func():
  while True:
    print('thread running')
  
t1 = thread_with_trace(target = func)
t1.start()
time.sleep(2)
t1.kill()
t1.join()
if not t1.isAlive():
  print('thread killed')
  
In this code, start() is slightly modified to set the system trace function using settrace(). 
The local trace function is defined such that,
whenever the kill flag (killed) of the respective thread is set, 
a SystemExit exception is raised upon the excution of the next line of code,
which end the execution of the target function func.
Now the thread can be killed with join().