Python thread with tracking of its execution

enchanted_thread.py

import sys
import threading


class enchanted_thread(threading.Thread):
    def __init__(self, *args, **keywords):
        threading.Thread.__init__(self, *args, **keywords)
        self.has_stopped = False

    def start(self):
        self.__run_backup = self.run
        self.run = self.__run
        threading.Thread.start(self)

    def stop(self):
        self.has_stopped = True

    def __run(self):
        """
        Sets a trace (sys.settrace) on a thread to track its execution.

        """
        sys.settrace(self.globaltrace)
        self.__run_backup()
        self.run = self.__run_backup

    def globaltrace(self, frame, event, arg):
        """
        This method will be called for every event on the thread, and if the event is a "call" then
        it will return a localtrace method to track the subsequent function call.

        """
        if event == "call":
            return self.localtrace
        else:
            return None

    def localtrace(self, frame, event, arg):
        """
        This method is also called for every event on the thread. If the killed flag is set to True
        and the event is "line", then a SystemExit exception is raised, which causes the thread to
        terminate.

        """       
        if self.has_stopped:
            if event == "line":
                raise SystemExit()
        return self.localtrace