pyQT5 Crashes when changing a variable

Question

I am very new to pyQT5 and running into some basic issues. I am trying to increment a variable by 1 (a) and then print the answer to the terminal whenever I press the cancel button, but this causes it to crash. I am unsure of what is going on. Thanks if you can help, sorry if this seems very basic to some, still learning.

from PyQt5 import QtCore, QtGui, QtWidgets
import datetime

class Ui_MainWindow(object):
  a=0
  def on_click(self):
    print("ButtonPressed")
  def func_accept(self):
    print("Displaying Time")
    current_time = str(datetime.datetime.now().time())
    ui.label1.setText(current_time)
  def func_canceled(self):
    print("Cancel")
    ui.label1.setText("Canceled")
    a=a+1
    print(a)

  def setupUi(self, MainWindow):
    MainWindow.setObjectName("MainWindow")
    MainWindow.resize(800, 600)
    self.centralwidget = QtWidgets.QWidget(MainWindow)
    self.centralwidget.setObjectName("centralwidget")
    self.button1 = QtWidgets.QDialogButtonBox(self.centralwidget)
    self.button1.setGeometry(QtCore.QRect(270, 370, 156, 23))
    self.button1.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
    self.button1.setObjectName("button1")
    self.label1 = QtWidgets.QLabel(self.centralwidget)
    self.label1.setGeometry(QtCore.QRect(310, 250, 141, 61))
    self.label1.setObjectName("label1")
    MainWindow.setCentralWidget(self.centralwidget)
    self.menubar = QtWidgets.QMenuBar(MainWindow)
    self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
    self.menubar.setObjectName("menubar")
    MainWindow.setMenuBar(self.menubar)
    self.statusbar = QtWidgets.QStatusBar(MainWindow)
    self.statusbar.setObjectName("statusbar")
    MainWindow.setStatusBar(self.statusbar)

    self.retranslateUi(MainWindow)
    QtCore.QMetaObject.connectSlotsByName(MainWindow)

    self.button1.clicked.connect(self.on_click)
    self.button1.accepted.connect(self.func_accept)
    self.button1.rejected.connect(self.func_canceled) 
  def retranslateUi(self, MainWindow):
    _translate = QtCore.QCoreApplication.translate
    MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
    self.label1.setText(_translate("MainWindow", "Apples"))


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_())

Thanks!

score 0 · Answer 1 · answered Dec 11 '19 at 04:18

The issue is with variable a, declare it in __init__ function and use. Check out the below code

from PyQt5 import QtCore, QtGui, QtWidgets
import datetime


class Ui_MainWindow(object):

    def __init__(self):
        self.a = 0

    def on_click(self):
        print("ButtonPressed")

    def func_accept(self):
        print("Displaying Time")
        current_time = str(datetime.datetime.now().time())
        ui.label1.setText(current_time)

    def func_canceled(self):
        print("Cancel")
        ui.label1.setText("Canceled")
        self.a += 1
        print(self.a)

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.button1 = QtWidgets.QDialogButtonBox(self.centralwidget)
        self.button1.setGeometry(QtCore.QRect(270, 370, 156, 23))
        self.button1.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel | QtWidgets.QDialogButtonBox.Ok)
        self.button1.setObjectName("button1")
        self.label1 = QtWidgets.QLabel(self.centralwidget)
        self.label1.setGeometry(QtCore.QRect(310, 250, 141, 61))
        self.label1.setObjectName("label1")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

        self.button1.clicked.connect(self.on_click)
        self.button1.accepted.connect(self.func_accept)
        self.button1.rejected.connect(self.func_canceled)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label1.setText(_translate("MainWindow", "Apples"))


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_())

pyQT5 Crashes when changing a variable

1 Answers1