PyQt5 UI crashes while code is running a function - python-3.x

Question

im pretty new to working with pyqt5 in python, everything is kinda running how it is supposed to be. the only issue i have is that when im triggering to start the function stepperaction(self, index) with the "START" button, i can see the code running in the console, but the UI crashes while the code is running if i click anywhere on the ui with my mouse. i would like to be able to press the "STOP" button in the UI even while the function is running. How am i able to fix this?
# -*- coding: utf-8 -*-
# Created by: PyQt5 UI code generator 5.13.0
import time
import sys
# import RPi.GPIO as GPIO
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import QVariant
stepcount = 0
class Ui_mainWindow(object):
def setupUi(self, mainWindow):
mainWindow.setObjectName("mainWindow")
mainWindow.resize(557, 320)
self.centralwidget = QtWidgets.QWidget(mainWindow)
self.centralwidget.setEnabled(True)
self.centralwidget.setObjectName("centralwidget")
self.pushButton = QtWidgets.QPushButton(self.centralwidget)
self.pushButton.setGeometry(QtCore.QRect(360, 40, 75, 23))
self.pushButton.setObjectName("pushButton")
self.pushButton_4 = QtWidgets.QPushButton(self.centralwidget)
self.pushButton_4.setGeometry(QtCore.QRect(360, 70, 75, 23))
self.pushButton_4.setObjectName("pushButton")
self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
self.pushButton_2.setGeometry(QtCore.QRect(270, 70, 75, 23))
self.pushButton_2.setObjectName("pushButton_2")
self.comboBox = QtWidgets.QComboBox(self.centralwidget)
self.comboBox.setGeometry(QtCore.QRect(150, 40, 101, 22))
self.comboBox.setEditable(False)
self.comboBox.setObjectName("comboBox")
self.comboBox.addItem("", QVariant(10*1600))
self.comboBox.addItem("", QVariant(20))
self.comboBox.addItem("", QVariant(30))
self.comboBox.addItem("", QVariant(40))
self.comboBox.addItem("", QVariant(50))
self.label = QtWidgets.QLabel(self.centralwidget)
self.label.setGeometry(QtCore.QRect(20, 30, 121, 31))
font = QtGui.QFont()
font.setPointSize(12)
self.label.setFont(font)
self.label.setObjectName("label")
self.progressBar = QtWidgets.QProgressBar(self.centralwidget)
self.progressBar.setGeometry(QtCore.QRect(20, 250, 118, 23))
self.progressBar.setProperty("value", 24)
self.progressBar.setObjectName("progressBar")
self.pushButton_3 = QtWidgets.QPushButton(self.centralwidget)
self.pushButton_3.setGeometry(QtCore.QRect(270, 40, 75, 23))
self.pushButton_3.setObjectName("pushButton_3")
self.label_2 = QtWidgets.QLabel(self.centralwidget)
self.label_2.setGeometry(QtCore.QRect(400, 252, 71, 21))
self.label_2.setObjectName("label_2")
self.label_3 = QtWidgets.QLabel(self.centralwidget)
self.label_3.setGeometry(QtCore.QRect(480, 252, 51, 21))
self.label_3.setObjectName("label_3")
mainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(mainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 557, 21))
self.menubar.setObjectName("menubar")
self.menuSmart_Spray_Booth_Configuration = QtWidgets.QMenu(self.menubar)
self.menuSmart_Spray_Booth_Configuration.setObjectName("menuSmart_Spray_Booth_Configuration")
mainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(mainWindow)
self.statusbar.setObjectName("statusbar")
mainWindow.setStatusBar(self.statusbar)
self.menubar.addAction(self.menuSmart_Spray_Booth_Configuration.menuAction())
self.retranslateUi(mainWindow)
QtCore.QMetaObject.connectSlotsByName(mainWindow)
self.comboBox.activated.connect(self.handleactivated)
self.pushButton.clicked.connect(lambda: self.stepperaction(index=self.comboBox.currentIndex()))
self.pushButton_2.clicked.connect(lambda: self.stop())
def handleactivated(self, index):
print(self.comboBox.itemText(index), "handle")
print(self.comboBox.itemData(index), "handle")
self.label_3.setText(self.comboBox.itemText(index))
def retranslateUi(self, mainWindow):
_translate = QtCore.QCoreApplication.translate
mainWindow.setWindowTitle(_translate("mainWindow", "Smart Spray Booth - Configuration"))
self.pushButton.setText(_translate("mainWindow", "START"))
self.pushButton_2.setText(_translate("mainWindow", "STOP"))
self.pushButton_3.setText(_translate("mainWindow", "Nullpunkt"))
self.comboBox.setItemText(0, _translate("mainWindow", "5cm"))
self.comboBox.setItemText(1, _translate("mainWindow", "10cm"))
self.comboBox.setItemText(2, _translate("mainWindow", "15cm"))
self.comboBox.setItemText(3, _translate("mainWindow", "20cm"))
self.comboBox.setItemText(4, _translate("mainWindow", "25cm"))
self.label.setText(_translate("mainWindow", "Bauteilgröße:"))
self.label_2.setText(_translate("mainWindow", "Bauteilgröße:"))
self.label_3.setText(_translate("mainWindow", "0 cm"))
self.menuSmart_Spray_Booth_Configuration.setTitle(_translate("mainWindow", "Smart Spray Booth - Configuration"))
if self.comboBox.currentTextChanged:
print(self.comboBox.currentData(), "from if")
def stop(self):
print("programm wird beendet")
sys.exit()
def stepperaction(self, index):
# GPIO.setmode(GPIO.BOARD) # read the pin as board instead of BCM pin
global stepcount
stepcount = self.comboBox.itemData(index)
print(stepcount, "this is given step")
# return stepcount
FastSpeed = 0.0001 # old = 0.001 Change this depends on your stepper motor
LowSpeed = 0.0001 # old = 0.001 Change this depends on your stepper motor
counter = 0
countery = 0
while True and counter < 3:
print("Move Up", stepcount, "steps")
for i in range(stepcount):
countery = countery + 1
print(countery)
time.sleep(LowSpeed)
print(countery)
time.sleep(LowSpeed)
time.sleep(1)
print("Move Down", stepcount, "steps")
for i in range(stepcount):
countery = countery + 1
print(countery)
time.sleep(FastSpeed)
print(countery)
time.sleep(FastSpeed)
time.sleep(1)
counter += 1
print("success")
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
mainWindow = QtWidgets.QMainWindow()
ui = Ui_mainWindow()
ui.setupUi(mainWindow)
mainWindow.show()
sys.exit(app.exec_())

Answer 1

I can't test on PyQt5, but on PySide you just need to pass the name of the function to connect, not execute it. It might also be better to avoid using lambdas in QT slots.
Try this modification:
....
self.pushButton.clicked.connect(self.stepperaction)
....
def stepperaction(self, index=None):
if index is None:
index = self.comboBox.currentIndex()
# GPIO.setmode(GPIO.BOARD) # read the pin as board instead of BCM pin
global stepcount
....