title: Python how to proof a boolean expression in a loop and cancel loop when button clicked
body: <p>Hello i have a Python program with a function "startAutomation" and inside this funtion i have the loop:</p>
  
  <pre><code>for i,j in zip(int_datadelta, int_timedelta):
    Att1.SetAttenuation(i) # Set attenuation
    print('Set Attenuation: ',i)
    lcd.display(i)
    time.sleep(j)
  </code></pre>
  
  <p>I have 4 buttons "Start", "Stop","Pause" and "Continue". I am able to start the function "startAutomation" with the button "Start" but the other buttons i can't get working. I need something to check the loop (boolean) and if "Stop" is clicked the loop should stop; when "Pause" is clicked the loop should pause as long as the button "Continue" is clicked or aborted when "Stop" is clicked.
  This is my code so far:</p>
  
  <pre><code># start button
  def startAutomation(self, lcd, browse_le, rssi_le, add_le, *btns):
    int_timedelta =[]
    int_datadelta =[]
      for i,j in zip(int_datadelta, int_timedelta):
        Att1.SetAttenuation(i) # Set attenuation
        print('Set Attenuation: ',i)
        lcd.display(i)
        time.sleep(j)
  
  def parsed():    
    btn3 = QtWidgets.QPushButton('Start')
    btn4 = QtWidgets.QPushButton('Stop')
    btn10 = QtWidgets.QPushButton('Pause')
    btn11 = QtWidgets.QPushButton('Continue')
    btn3.clicked.connect(functools.partial(self.startAutomation, lcd, le, le4, le5, rbtn, rbtn2, rbtn3))
    btn4.clicked.connect(functools.partial(self.stopAutomation))
    btn10.clicked.connect(functools.partial(self.pauseAutomation))
    btn11.clicked.connect(functools.partial(self.continueAutomation))
    hbox3.addWidget(btn3)
    hbox3.addWidget(btn4)
    hbox3.addWidget(btn10)
    hbox3.addWidget(btn11)      
    ...
    return vbox
  
  # stop button
  def stopAutomation(self):
      print ("Stop")
  
  # pause button
  def pauseAutomation(self):
    print ("Pause")
  
  # continue button
  def continueAutomation(self):
      print ("Continue")
  </code></pre>
  
  <p>I tried several things whith a while loop but i can't get it working. It would be glad if someone could help ?</p>