PyQt5 QCoreApplication.quit() not working

I put a quit button on my PyQt5 application that needs to quit the app with exit code 0. I found QCoreApplication.quit() that needs to quit the application. This method works but doesn't give exit code 0. It rather freezes my computer for a few seconds just before exiting with Process finished with exit code -1073741819 (0xC0000005) which is obviously a memory error. The app only does this when it I quit it using the button I made, this doesnt happen when using alt+f4.

class MorePage(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent=parent)
        button = QPushButton("X", self)
        button.setGeometry(0,0,70,70)
        button.clicked.connect(quit)
    def quit(): QCoreApplication.quit()

Calling QCoreApplication.quit () is the same as calling QCoreApplication.exit (0). To quote from the qt docs: After this function has been called, the application leaves the main event loop and returns from the call to exec(). The exec() function returns returnCode, if that makes sense.

A different way to do it would be to perhaps use sys.exit() However, it is considered to be a bad idea in the case of Qt. Still, you can try this:

from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import Qt
import sys

class PushButton(QWidget):
    def __init__(self):
        super(PushButton,self).__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("PushButton")
        self.setGeometry(400,400,300,260)
        button = QPushButton("X", self)
        button.setGeometry(0,0,70,70)
        button.clicked.connect(sys.exit)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = PushButton()
    ex.show()
    sys.exit(app.exec_()) 

You could also use QApplication.quit() along with self.close() to quit the application AND close the window, which would be a much better idea then sys.exit() Try this:

def initUI(self):
        self.setWindowTitle("PushButton")
        self.setGeometry(400,400,300,260)
        button = QPushButton("X", self)
        button.setGeometry(0,0,70,70)
        button.clicked.connect(self.quit)
    def quit(self):
        QApplication.quit()
        self.close()