Python Thread example

thread

class Thread(QThread):
  dataReady = Signal(object)

  def run(self):
    while True:
      self.data = slowly_produce_data()
      # this will add a ref to self.data and avoid the destruction 
      self.dataReady.emit(self.data) 

class Widget(QWidget):
  def __init__(self):
    self.thread = Thread()
    self.thread.dataReady.connect(self.get_data, Qt.QueuedConnection)
    self.thread.start()

  def get_data(self, data):
    self.data = data

  def paintEvent(self, event):
    paint_somehow(self.data)