Change text of QPushButton on Click

So I have been searching around but can't seem to find a solution to my problem. I would like to update the text of a QPushButton when it is clicked. Every time i run my code it crashes with no error message. Please Could someone help me? i have attached the relevant section of my code below:

def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.OuterSwitch.setText(_translate("MainWindow", "OuterDoorControl"))
        self.InnerSwitch.setText(_translate("MainWindow", "InnerDoorControl"))


class ControlMainWindow(QtWidgets.QMainWindow):
    def __init__(self,parent=None):
        self.ui = Ui_MainWindow()


    def OuterControl(self):
        if GPIO.input(Inner)==0: #InnerDoorOpen
            return GPIO.output(Outer,GPIO.HIGH),print("Please Close Inner Door")
        elif GPIO.input(Outer) ==1: #Outer Door Close
            self.OuterSwitch.setText(_translate("MainWindow","Close Outer Door"))
            return GPIO.output(Outer,GPIO.LOW) #Open Outer Door
        elif GPIO.input(Outer) == 0: #OuterDoor Open
            return GPIO.output(Outer,GPIO.HIGH) #Close OuterDoor

The OuterSwitch and InnerSwitch are the two push buttons I am using. I am using PyQt5 and designed the Gui using QtDesigner. I am using Python 3.7.

Please can you help?