How to create new PyQt4 windows from an existing window?

Question

I\'ve been trying to call a new window from an existing one using python3 and Qt4.

I\'ve created two windows using Qt Designer (the main application and another one)

Answer 1

You can only create one QApplication. After you have created it you can create how many windows you want.

For example:

from PyQt4 import QtGui, QtCore

class MyWindow(QtGui.QDialog):    # any super class is okay
    def __init__(self, parent=None):
        super(MyWindow, self).__init__(parent)
        self.button = QtGui.QPushButton('Press')
        layout = QtGui.QHBoxLayout()
        layout.addWidget(self.button)
        self.setLayout(layout)
        self.button.clicked.connect(self.create_child)
    def create_child(self):
        # here put the code that creates the new window and shows it.
        child = MyWindow(self)
        child.show()


if __name__ == '__main__':
    # QApplication created only here.
    app = QtGui.QApplication([])
    window = MyWindow()
    window.show()
    app.exec_()

Every time you click the button will create a new window.

You can adapt the above example to use the windows you created with the Designer.

On a side note:

Never ever edit the result of pyuic. Those files should not be changed. This means: do not add the mbutton1 method to the Ui_Form.

If you have the file mywindow_ui.py that was created by pyuic, then you create the file mywindow.py and put something like this:

from PyQt4 import QtCore, QtGui
from mywindow_ui import Ui_MyWindow

class MyWindow(QtGui.QWidget, Ui_MyWindow):   #or whatever Q*class it is
    def __init__(self, parent=None):
        super(MyWindow, self).__init__(parent)
        self.setupUi(self)
    def create_child(self):   #here should go your mbutton1
        # stuff
#etc.

Now from your main file main.py you do:

from PyQt4 import QtGui

from mywindow import MyWindow


# ...

if __name__ == '__main__':
    app = QtGui.QApplication([])
    window = MyWindow()
    window.show()
    app.exec_()