python - PyQT: how to open new window

Question

First of all, similar questions have been answered before, yet I need some help with this one.

I have a window which contains one button (Class First) and I want on pressed, a second blank window to be appeared (Class Second).

I fiddled with the code copied from this question: PyQT on click open new window, and I wrote this code:

# -*- coding: utf-8 -*-

from PyQt4 import QtGui, QtCore
import sys
import design1, design2

class Second(QtGui.QMainWindow, design2.Ui_MainWindow):
    def __init__(self, parent=None):
        super(Second, self).__init__(parent)
        self.setupUi(self)

class First(QtGui.QMainWindow, design1.Ui_MainWindow):
    def __init__(self, parent=None):
        super(First, self).__init__(parent)
        self.setupUi(self)

        self.pushButton.clicked.connect(self.on_pushButton_clicked)
        self.dialog = Second(self)

    def on_pushButton_clicked(self):
        self.dialog.exec_()

def main():
    app = QtGui.QApplication(sys.argv)
    main = First()
    main.show()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

but on_pressed, this error message appears:

AttributeError: 'Second' object has no attribute 'exec_'

(design1 and design2 have been derived from the Qt designer.)

Any thought would be appreciated.

While QDialog has an exec_ method, you have subclassed QMainWindow which does not have that method. You might want to read up on the differences between tge classes and decide what you want to use. — three_pineapples

salomonderossi salomonderossi · Accepted Answer · 2016-04-21T11:30:24

Here I'm using the show method.

Here is a working example (derived from yours):

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
from PyQt4 import QtGui, QtCore
import sys
 
 
class Second(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(Second, self).__init__(parent)
 
 
class First(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(First, self).__init__(parent)
        self.pushButton = QtGui.QPushButton("click me")
 
        self.setCentralWidget(self.pushButton)
 
        self.pushButton.clicked.connect(self.on_pushButton_clicked)
        self.dialog = Second(self)
 
    def on_pushButton_clicked(self):
        self.dialog.show()
 
 
def main():
    app = QtGui.QApplication(sys.argv)
    main = First()
    main.show()
    sys.exit(app.exec_())
 
if __name__ == '__main__':
    main()

If you need a new window every time you click the button, you can change the code that the dialog is created inside the on_pushButton_clicked method, like so:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
from PyQt4 import QtGui, QtCore
import sys
 
 
class Second(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(Second, self).__init__(parent)
 
 
class First(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(First, self).__init__(parent)
        self.pushButton = QtGui.QPushButton("click me")
 
        self.setCentralWidget(self.pushButton)
 
        self.pushButton.clicked.connect(self.on_pushButton_clicked)
        self.dialogs = list()
 
    def on_pushButton_clicked(self):
        dialog = Second(self)
        self.dialogs.append(dialog)
        dialog.show()
 
 
def main():
    app = QtGui.QApplication(sys.argv)
    main = First()
    main.show()
    sys.exit(app.exec_())
 
if __name__ == '__main__':
    main()

python - PyQT: how to open new window

1 Answers