import sys
import os

# os.environ['QT_PREFERRED_BINDING'] = 'PyQt4'
# os.environ['QT_PREFERRED_BINDING'] = 'PySide'
# os.environ['QT_PREFERRED_BINDING'] = 'PyQt5'
# os.environ['QT_PREFERRED_BINDING'] = 'PySide2'

from Qt import QtCore
from Qt import QtWidgets
from Qt import __binding__
if __binding__.startswith('PyQt'):
    from Qt import uic
elif __binding__.startswith('PySide'):
    from Qt import QtUiTools

print 'Using', __binding__


class TestApp(QtWidgets.QMainWindow):
    """docstring for ClassName"""
    def __init__(self):
        super(TestApp, self).__init__()

        if __binding__.startswith('PyQt'):
            # Main window
            self.ui = uic.loadUi('main_window.ui', self)
            # UI Module
            ui_module = uic.loadUi('module.ui')
        elif __binding__.startswith('PySide'):
            # Main window
            main_file = QtCore.QFile('main_window.ui')
            main_file.open(QtCore.QFile.ReadOnly)
            self.ui = QtUiTools.QUiLoader().load(main_file)
            # UI Module
            module_file = QtCore.QFile('module.ui')
            module_file.open(QtCore.QFile.ReadOnly)
            ui_module = QtUiTools.QUiLoader().load(module_file)
            module_file.close()

        # Attach module to main window
        self.ui.verticalLayout.addWidget(ui_module)

        # Edit widget
        self.ui.label = ui_module.label
        self.ui.label.setText('Hello')

        self.ui.show()

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    win = TestApp()
    sys.exit(app.exec_())