Pyqt Mainwindow Not Showing Widgets

I am making a GUI with PyQt, and I am having issues with my MainWindow class. The window doesn't show widgets that I define in other classes, or it will show a small portion of the

Solution 1:

A QMainWindow has a central widget that is a container in which you should add your widgets. It has its own layout. The layout of the QMainWindow is for toolbars and such. The centralWidget must be set with the setCentralWidget method. It isn't enough to just call it self.centralWidget

Use the following three lines instead.

self.setCentralWidget(QtGui.QWidget(self))
self.hbox = QtGui.QHBoxLayout()
self.centralWidget().setLayout(self.hbox)