class WorkThread( QThread ):
  def __init__( self, inData, radius, rotate ):
    QThread.__init__( self, QThread.currentThread() )
    self.mutex = QMutex()
    self.stopMe = 0
  def run( self ):
    self.mutex.lock()
    self.stopMe = 0
    self.mutex.unlock()
    interrupted = False
    for i in inData:
      # что-то делаем
      self.emit( SIGNAL( "updateProgress()" ) )
    
      self.mutex.lock()
      s = self.stopMe
      self.mutex.unlock()
      if s == 1:
        interrupted = True
        break
    if not interrupted:
      self.emit( SIGNAL( "processFinished()" ) )
    else:
      self.emit( SIGNAL( "processInterrupted()" ) )
  def stop( self ):
    self.mutex.lock()
    self.stopMe = 1
    self.mutex.unlock()
    QThread.wait( self )

self.myThread = WorkThread( myData, myRadius, False )
QObject.connect( self.workThread, SIGNAL( "updateProgress()" ), self.updateProgress )
QObject.connect( self.workThread, SIGNAL( "processFinished()" ), self.processFinished )
QObject.connect( self.workThread, SIGNAL( "processInterrupted()" ), self.processInterrupted )
self.workThread.start()

class A(QThread):
    updateProgress = QtCore.pyqtSignal()
    ...
    def f(sefl):
        self.updateProgress.emit()
        ...
self.workThread.updateProgress.connect(self.updateProgress)
...