Python 3.5 + QT designer+ PyQT4

[Armind]

Hi everyone :)
This is my first post here :)
I create a main program called tyg. This is a Form with button. Also i created second program V1 and form called V1( Ui_V1). I would see this Form ( from V1) after when i click the button in program 'tyg'. I do everything from this anwser http://stackoverflow.com/questions/27567208/how-do-i-open-sub-window-after-i-click-on-button-on-main-screen-in-pyqt4
but when i compile i get an error called

'Ui_V1' object has no attribute 'show'

This is a part of code from tyg.py

from PyQt4 import QtCore, QtGui
from V1 import Ui_V1

#V1_v1 program
class Ui_V1(object):
    def setupUi(self, V1):
        V1.setObjectName(_fromUtf8("V1")) etc

#MAIN WINDOW_tyg program
class Ui_Form(object):
    def setupUi(self, Form): etc
     Form.setObjectName(_fromUtf8("Form"))
     self.pushButton_5.clicked.connect(lambda: self.openV1())

def openV1(self):
        window=Ui_V1()
        window.show()

Where is the problem?