import pickle

import threading

class Dumper(threading312.Thread):
    def __init__(self, to_dump, dir, fname):
        self.to_dump = to_dump
        self.dir = dir
        self.fname = fname
        threading.Thread.__init__(self)

    def run(self):
        self.setDaemon(True)
        f=open(self.dir+"\\Notes\\" + self.fname,"wb")
        pickle.dump(self.to_dump,f)
        f.close()

Dumper(my_obj, dir, fname).start()