How to change .ui file that is displayed on button click in pyqt5 python3

Question

I want to change dispaly on button click. my current code:

import sys
from PyQt5 import QtWidgets, uic

Ui_bankApp, _ = uic.loadUiType("bankApp.ui")
Ui_Borrow, _ = uic.loadUiType("Borrow.ui")
Ui_Login, _ = uic.loadUiType("login.ui")
Ui_Pay, _ = uic.loadUiType("Pay.ui")

class Borrow(object):
    def setupUI(self, Ui):
        uic.loadUi('Borrow.ui', self)

class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super(Ui, self).__init__()
        self.bankApp()

    def bankApp(self):
        print("bankApp")
        self.ui = Ui_bankApp()
        self.ui.setupUi(self)
        self.hide()
        self.show()
        self.button = self.findChild(QtWidgets.QPushButton, 'pushButton_2') 
        self.button.clicked.connect(self.Borrow)


    def Borrow(self):
        print("Borrow")
        self.ui1 = Ui_Borrow()
        self.ui1.setupUi(self)
        self.button1 = self.findChild(QtWidgets.QPushButton, 'pushButton_2') 
        self.button1.clicked.connect(self.bankApp)


    def Login(selft):
        self.ui = Ui_Login()
        self.ui.setupUi(self)

    def Pay():
        self.ui = Ui_Pay()
        self.ui.setupUi(self)


app = QtWidgets.QApplication(sys.argv)
window = Ui()
window.show()
app.exec_()

my two ui files look like: bankApp.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>80</x>
      <y>190</y>
      <width>75</width>
      <height>23</height>
     </rect>
    </property>
    <property name="text">
     <string>Pay</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton_2">
    <property name="geometry">
     <rect>
      <x>610</x>
      <y>180</y>
      <width>75</width>
      <height>23</height>
     </rect>
    </property>
    <property name="text">
     <string>Borrow</string>
    </property>
   </widget>
   <widget class="QLCDNumber" name="lcdNumber">
    <property name="geometry">
     <rect>
      <x>210</x>
      <y>30</y>
      <width>321</width>
      <height>91</height>
     </rect>
    </property>
    <property name="intValue" stdset="0">
     <number>1000</number>
    </property>
   </widget>
   <widget class="QLCDNumber" name="lcdNumber_2">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>270</y>
      <width>131</width>
      <height>51</height>
     </rect>
    </property>
   </widget>
   <widget class="QLCDNumber" name="lcdNumber_3">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>370</y>
      <width>131</width>
      <height>51</height>
     </rect>
    </property>
   </widget>
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>230</y>
      <width>91</width>
      <height>31</height>
     </rect>
    </property>
    <property name="text">
     <string>Spent</string>
    </property>
   </widget>
   <widget class="QLabel" name="label_2">
    <property name="geometry">
     <rect>
      <x>600</x>
      <y>340</y>
      <width>47</width>
      <height>13</height>
     </rect>
    </property>
    <property name="text">
     <string>Earned</string>
    </property>
   </widget>
   <widget class="QLabel" name="label_3">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>250</y>
      <width>47</width>
      <height>13</height>
     </rect>
    </property>
    <property name="text">
     <string>Debt</string>
    </property>
   </widget>
   <widget class="QLCDNumber" name="lcdNumber_4">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>270</y>
      <width>141</width>
      <height>51</height>
     </rect>
    </property>
   </widget>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

Borrow:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Borrow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>20</x>
      <y>20</y>
      <width>51</width>
      <height>41</height>
     </rect>
    </property>
    <property name="text">
     <string>Back</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton_2">
    <property name="geometry">
     <rect>
      <x>220</x>
      <y>290</y>
      <width>281</width>
      <height>51</height>
     </rect>
    </property>
    <property name="text">
     <string>Borrow</string>
    </property>
   </widget>
   <widget class="QLineEdit" name="lineEdit">
    <property name="geometry">
     <rect>
      <x>220</x>
      <y>200</y>
      <width>281</width>
      <height>51</height>
     </rect>
    </property>
    <property name="text">
     <string>Amount</string>
    </property>
   </widget>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

so i want to switch to borrow page when i click the borrow button in the bankApp then i want to switch to bankApp page when i press the back button. but when i click the back button on the borrow page it does not go back to the bankApp page

Answer 1

You could consider using a QStackedWidget to switch between the layouts instead of changing the ui of the on the fly. For example,

class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        self.stacked_widget = QtWidgets.QStackedWidget()
        self.bankApp()
        self.Borrow()
        self.setCentralWidget(self.stacked_widget)
        self.resize(800,600)

    def bankApp(self):
        self.bank_widget = QtWidgets.QMainWindow()
        Ui_bankApp().setupUi(self.bank_widget)
        self.stacked_widget.addWidget(self.bank_widget)
        self.button = self.bank_widget.findChild(QtWidgets.QPushButton, 'pushButton_2')
        self.button.clicked.connect(lambda : self.goto_page(self.borrow_widget))

    def Borrow(self):
        self.borrow_widget = QtWidgets.QMainWindow()
        Ui_Borrow().setupUi(self.borrow_widget)
        self.stacked_widget.addWidget(self.borrow_widget)
        self.button1 = self.borrow_widget.findChild(QtWidgets.QPushButton, 'pushButton_2')
        self.button1.clicked.connect(lambda : self.goto_page(self.bank_widget))

    def goto_page(self, widget):
        index = self.stacked_widget.indexOf(widget)
        print(index, widget)
        if index >= 0:
            self.stacked_widget.setCurrentIndex(index)