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how to close a window in pyqt5 and terminate the program? program gets stuck

I want to create a window in pyqt5 and then close it. For some reason the program does not exit after closing the window. It gets stuck. I have been reading several related posts but none give a clear answer.
I have already tried code such as "self.object.close()", "app.quit()", even "self.object.destroy()", but all work in the same way. The only thing that really closes the window is by clicking the x (close) at the window itself. But this is not the behavior I need. I would like to close the window using my code.
import sys
from PyQt5 import QtWidgets
from PyQt5 import QtCore
from PyQt5 import QtGui
from PyQt5.QtCore import pyqtSlot, pyqtSignal
class window(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.setGeometry(300, 300, 480, 300)
self.setWindowTitle('Hello World')
self.setWindowLayout()
def setWindowLayout(self):
self.w = QtWidgets.QWidget(self)
self.layout = QtWidgets.QHBoxLayout()
self.label = QtWidgets.QLabel('Hello World Label')
self.layout.addWidget(self.label)
self.w.setLayout(self.layout)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
main_window = window()
main_window.show()
main_window.close()
sys.exit(app.exec_())
Once I close the window using
main_window.close(). I want my program to exit.
I apologize if this was resolved in a different post. I searched the answer and none solves my problem.
Thanks.

It seems to me that it is a bug since according to the docs the application should be closed if there is no top-level window but it seems that it is not verified if the closing of the window is not after the event-loop starts. A workaround is to use QTimer.singleShot(0, ...) to close the window:
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class window(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.setGeometry(300, 300, 480, 300)
self.setWindowTitle('Hello World')
self.setWindowLayout()
def setWindowLayout(self):
self.w = QtWidgets.QWidget(self)
self.layout = QtWidgets.QHBoxLayout()
self.label = QtWidgets.QLabel('Hello World Label')
self.layout.addWidget(self.label)
self.w.setLayout(self.layout)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
main_window = window()
main_window.show()
QtCore.QTimer.singleShot(0, main_window.close) # <---
sys.exit(app.exec_())

How to show the correct frame with python and pyQt

I'm a beginner in python , and I try to generate the frame with pyQt.
Here is my code , and I have some trouble that can not show a correct frame .
At first I wrote , and it can showed the result that I want.
#!/usr/bin/python
import sys
from PyQt4 import QtGui
app = QtGui.QApplication(sys.argv)
widget = QtGui.QWidget()
widget.resize(250, 150)
widget.setWindowTitle('simple2')
widget.show()
sys.exit(app.exec_())
I changed the wording of object-oriented later , and it can't show a frame which I except.
#!/usr/bin/python
import sys
from PyQt4 import QtGui
class Apple(QtGui.QWidget):
def _int_(self,parent=None):
super().__init__()
self.widget = QtGui.QWidget()
self.resize(250, 150)
self.setWindowTitle('simple2')
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
mywidget = Apple()
mywidget.show()
sys.exit(app.exec_())
Someone knows how do I fix my error ?

You have made a typo in your code
def _int_(self,parent=None):
should be
def __init__(self, parent=None):

Edit your code this way:
#!/usr/bin/python
# -* coding: utf-8 -*-
import sys
from PyQt4 import QtGui
class Apple(QtGui.QMainWindow):
def _init_(self): # if you have no parent you don't need to write parent = None. And yes, there was a typo
super(Apple, self).__init__() # it's a little bit better than super().__init__()
#self.widget = QtGui.QWidget() # you've already init QWidget. This code do nothing
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
mywidget = Apple()
mywidget.setWindowTitle('simple2') # here must be window title
mywidget.resize(250, 150) # and resizing
mywidget.show()
sys.exit(app.exec_())
Now you get what you want

PyQT + VTK : QVTKRenderWindowInteractor is invisible

I've made a little program to visualize 3D data with pyqt and VTK. The QVTKRenderWindowInteractor is embed in a QMainWindow centralWidget.
Everything works fine but if I add :
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.setAttribute(QtCore.Qt.WA_TranslucentBackground, True)
I get a hole (the QVTKRenderWindowInteractor is 100% transparent). All the other widgets are displayed correctly (menuBar, statusBar, etc..)
I've tried several combinations and it seems like the issue doesn't comes from my stylesheet. I have absolutly no idea about what is going on here.
Any help is welcome :)
EDIT : Here is a sample (python 2.7 and vtk. I'm using python(x,y)) :
#!/usr/bin/env python
import sys
import vtk
from vtk.qt4.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
from PyQt4 import Qt
from PyQt4 import QtGui, QtCore
class test(Qt.QMainWindow):
"""Test class"""
def __init__(self, parent=None):
Qt.QMainWindow.__init__(self, parent)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.setAttribute(QtCore.Qt.WA_TranslucentBackground, True)
self.setWindowTitle(self.tr("PyQt4 VTK test"))
self.workspace = Qt.QWorkspace()
self.setCentralWidget(self.workspace)
self.frame = QtGui.QFrame(self.workspace)
self.hbox = QtGui.QHBoxLayout()
# create the widget
self.widget = QVTKRenderWindowInteractor(self.frame)
self.widget.Initialize()
self.widget.Start()
# if you dont want the 'q' key to exit comment this.
self.widget.AddObserver("ExitEvent", lambda o, e, a=app: a.quit())
self.cone = vtk.vtkConeSource()
self.cone.SetResolution(8)
self.coneMapper = vtk.vtkPolyDataMapper()
self.coneMapper.SetInput(self.cone.GetOutput())
self.coneActor = vtk.vtkActor()
self.coneActor.SetMapper(self.coneMapper)
self.ren = vtk.vtkRenderer()
self.ren.AddActor(self.coneActor)
self.renWin=self.widget.GetRenderWindow()
self.renWin.AddRenderer(self.ren)
self.hbox.addWidget(self.widget)
self.frame.setLayout(self.hbox)
self.workspace.addWindow(self.frame)
if __name__ == "__main__":
app = Qt.QApplication(sys.argv)
mainwindow = test()
mainwindow.show()
sys.exit(app.exec_())

How to make a window that occupies the full screen without maximising?

I'm writing in python using Qt
I want to create the application window (with decorations) to occupy the full screen size. Currently this is the code I have:
avGeom = QtGui.QDesktopWidget().availableGeometry()
self.setGeometry(avGeom)
the problem is that it ignores window decorations so the frame is larger... I googled and what not, found this:
http://harmattan-dev.nokia.com/docs/library/html/qt4/application-windows.html#window-geometry
which seems to indicate I need to set the frameGeometry to the avGeom however I haven't found a way to do that. Also, in the comments in the above link it says what I'm after may not be even possible as the programme can't set the frameGeometry before running... If that is the case I just want confirmation that my problem is not solvable.
EDIT:
So I played around with the code a bit and this gives what I want... however the number 24 is basically through trial and error until the window title is visible.... I want some better way to do this... which is window manager independent..
avGeom = QtGui.QDesktopWidget().availableGeometry()
avGeom.setTop(24)
self.setGeometry(avGeom)
Now I can do what I want but purely out of trial and error
Running Ubuntu, using Spyder as an IDE
thanks

Use QtGui.QApplication().desktop().availableGeometry() for the size of the window:
#!/usr/bin/env python
#-*- coding:utf-8 -*-
from PyQt4 import QtGui, QtCore
class MyWindow(QtGui.QWidget):
def __init__(self, parent=None):
super(MyWindow, self).__init__(parent)
self.pushButtonClose = QtGui.QPushButton(self)
self.pushButtonClose.setText("Close")
self.pushButtonClose.clicked.connect(self.on_pushButtonClose_clicked)
self.layoutVertical = QtGui.QVBoxLayout(self)
self.layoutVertical.addWidget(self.pushButtonClose)
titleBarHeight = self.style().pixelMetric(
QtGui.QStyle.PM_TitleBarHeight,
QtGui.QStyleOptionTitleBar(),
self
)
geometry = app.desktop().availableGeometry()
geometry.setHeight(geometry.height() - (titleBarHeight*2))
self.setGeometry(geometry)
#QtCore.pyqtSlot()
def on_pushButtonClose_clicked(self):
QtGui.QApplication.instance().quit()
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
app.setApplicationName('MyWindow')
main = MyWindow()
main.show()
sys.exit(app.exec_())

I've always found inheritting from the QMainWindow class to be particularly useful. Like this:
import sys
from PySide.QtGui import *
from PySide.QtCore import *
class Some_APP(QMainWindow):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
### this line here is what you'd be looking for
self.setWindowState(Qt.WindowMaximized)
###
self.show()
def main():
app = QApplication(sys.argv)
some_app = Some_APP()
sys.exit(app.exec_())
if __name__ == "__main__":
main()

PyQt4: how to make undercorated window with reserved space

I'd like to make a panel-like application using PyQt4 for Linux. for this i need the window i created:
to be undecorated
to have reserved space
to appear on all workspaces
From reading the documentation i've got the idea that i should use QtWindowFlags. But i have no clue as to how to do that. Also i believe there should be a Qt.WindowType hint somewhere telling the WM the window's a "dock" application. I have made this with pygtk following this thread, but here with Qt i don't really know how to handle this. (I need Qt for its ability to theme/skin application more easily.)
Below is the current code i made (nothing extraordinary).
import sys
from PyQt4 import QtGui
class Panel(QtGui.QWidget):
def __init__(self, parent=None): ## should the QtWindowFlag be here?
QtGui.QWidget.__init__(self, parent) ## should the QtWindowFlag be there as well?
self.setWindowTitle('QtPanel')
self.resize(QtGui.QDesktopWidget().screenGeometry().width(), 25)
self.move(0,0)
def main():
app = QtGui.QApplication(sys.argv)
panel = Panel()
panel.show()
sys.exit(app.exec_())
return 0
if __name__ == '__main__':
main()
Can anyone help me with this? Thanks :)

Read about the QWidget.windowFlags property: http://doc.qt.nokia.com/4.7/qwidget.html#windowFlags-prop
Example:
>>> from PyQt4 import QtGui, QtCore
>>> app = QtGui.QApplication([])
>>> win = QtGui.QMainWindow()
>>> win.setWindowFlags(win.windowFlags() | QtCore.Qt.FramelessWindowHint)
>>> win.show()

import sys
from PyQt4 import QtGui, QtCore
class Example(QtGui.QWidget):
def __init__(self):
super(Example, self).__init__()
self.initUI()
def initUI(self):
qbtn = QtGui.QPushButton('Quit', self)
#qbtn.clicked.connect(QtCore.QCoreApplication.instance().quit)
qbtn.clicked.connect(self.test)
qbtn.resize(qbtn.sizeHint())
qbtn.move(50, 50)
self.setGeometry(300, 300, 250, 150)
self.setWindowTitle('Quit button')
self.setWindowFlags(self.windowFlags() | QtCore.Qt.FramelessWindowHint)
self.show()
def test(self):
print "test"
def main():
app = QtGui.QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

The solution is to use Python-Xlib, and it has been described in an answer on a universal way to reserve screen space on X.