title: PyQt: Change GUI Layout after button is clicked
body: <p>Okay, I am jumping from Tkinter to PyQt, because PyQt is just so much more advanced, and nicer to work with. BUT! I am having some troubles here.</p>
  
  <p>I am trying to change the GUI layout after I press one of my buttons on the main screen. I press the first button of the main GUI page, then I want it to go to another GUI page that I will create. I have been sitting here for hours trying to find some way to do this - no videos on YouTube, and I haven't found any stack-overflow pages that help. So I learnt that there is a Qt Designer program. I don't like programs like that, so please try to stay away from using that when answering.</p>
  
  <p>PS: I don't want to be working with more than one .py file, but if there is no other way, I guess I'm going to have to do so.</p>
  
  <p>Here is my code so far:</p>
  
  <pre><code>class Window(QtGui.QMainWindow):
  
      def __init__(self):
          super(Window, self).__init__()
          self.setGeometry(50, 50, 400, 450)
          self.setFixedSize(400,450)
          self.setWindowTitle(" Tool")
          self.setWindowIcon(QtGui.QIcon('PhotoIcon.png'))
          self.home()
  
      def home(self):
          ToolsBTN = QtGui.QPushButton('text', self)
          ToolsBTN.clicked.connect(ToolTab)
          ToolsBTN.move(50, 350)
          CPSBTN = QtGui.QPushButton('text', self)
          CPSBTN.clicked.connect(QtCore.QCoreApplication.instance().quit)
          CPSBTN.move(150, 350)
          CreatorBTN = QtGui.QPushButton('Creator', self)
          CreatorBTN.clicked.connect(QtCore.QCoreApplication.instance().quit)
          CreatorBTN.move(250, 350)
          self.show()
  
  class ToolTab(QtGui.QMainWindow):
  
      def __init__2(self):
          super(ToolTab, self).__init__2()
          self.setGeometry(50, 50, 400, 450)
          self.setFixedSize(400,450)
          self.setWindowTitle(" Tool")
          self.setWindowIcon(QtGui.QIcon('PhotoIcon.png'))
          self.Toolsgui()
  
      def Toolsgui(self):
          CPSBTN = QtGui.QPushButton('123', self)
          CPSBTN.clicked.connect(QtCore.QCoreApplication.instance().quit)
          CPSBTN.move(150, 300)
          self.show()
  
  def Run():
      app = QtGui.QApplication(sys.argv)
      GUI = Window()
      GUITOOL = ToolTab()
      sys.exit(app.exec_())
  
  Run()
  </code></pre>