python - Function offloaded to PyQt QThread is 2x slower -

i've been trying optimize application, , although made function run on average 10.06 seconds when profiled itself, when put on qthread, takes around 17-22 seconds.

it's 2x slower in qthread. how fix that?

the function initializing class called docxdocument, document read word file , parsed needs.

i have qthread creates class , uses qt signals send progress information gui. here code class:

class docximporterthread(qthread): ''' thread used import .docx document, report progress, , return document parsed. ''' reportprogress = pyqtsignal(int) reporterror = pyqtsignal(exception, str) reporttext = pyqtsignal(str)  def __init__(self, filepath):     qthread.__init__(self)     self.setpriority(qthread.highestpriority)     self._filepath = filepath     self._docx = none     self._html = ''     self._bookmarks = none     self._pages = none     self._stop = false  def run(self):      def myprogresshook(percentage):         self.reportprogress.emit(percentage)      def mycancelhook():         return self._stop      try:         self._docx = docxdocument(self._filepath, myprogresshook, mycancelhook)          if not self._stop:             self._html = self._docx.getmainpage()             self._bookmarks = self._docx.getheadings()             self._pages = self._docx.getpages()      except exception ex2:         print 'error: .docx document didn\'t import.'         self.reporterror.emit(ex2, traceback.format_exc()) 

the getmainpage(), getheadings(), , getpages() instantaneous because return reference constructor created. here code used profile docxdocument class:

testfile = 'some_file.docx' statsave = 'profile.out'  def progress(percent):     print ' --', percent, '--'  cprofile.run('docxdocument(testfile)', filename=statsave) mystats = pstats.stats(statsave) mystats.sort_stats('cumulative', 'name') mystats.print_stats() 

thanks time in looking @ this!