import threading, zipfile

class AsyncZip(threading.Thread):

    def __init__(self, infile, outfile):

        threading.Thread.__init__(self)

        self.infile = infile

        self.outfile = outfile

    def run(self):

        f = zipfile.ZipFile(self.outfile, 'w', zipfile.ZIP_DEFLATED)

        f.write(self.infile)

        f.close()

        print('Finished background zip of:', self.infile)

background = AsyncZip('mydata.txt', 'myarchive.zip')

background.start()

print('The main program continues to run in foreground.')

background.join()    # Wait for the background task to finish

print('Main program waited until background was done.')