Close second widget after pressing save button pyqt5 - python-3.x

Question

I am writing an application where main widget windows opens second widget window and in the second widget window, I am taking some inputs from user and on hitting save button, second widget window should saves the data into xml file and should get closed but the second window is not closing.
I tried most of the things from google like self.close(), self.destroy(),self.hide() self.window().hide(), self.window().destroy() none of them are working.
I don't want to do sys.exit() as this is closing complete application but just have to close secondWidgetWindow after clicking save button so that user can do another work in first widget window.
Below is the snippet :
FirstWidgetWindow.py
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_firstWidgetWindow(QtWidgets.QMainWindow):
def __init__(self,firstWidgetWindow):
super().__init__()
self.setupUi(firstWidgetWindow)
def setupUi(self, firstWidgetWindow):
### code to create Button ###
self.btnOpenNewWidgetWindow.clicked.connect(self.openNewWindow)
def openNewWindow(self):
self.secondWidgetWindow = QtWidgets.QWidget()
self.ui = Ui_secondWidgetWindow()
self.ui.setupUi(self.secondWidgetWindow)
self.secondWidgetWindow.show()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
firstWidgetWindow = QtWidgets.QWidget()
ui = Ui_firstWidgetWindow(firstWidgetWindow)
firstWidgetWindow.show()
sys.exit(app.exec_())
secondWidgetWindow.py
class Ui_secondWidgetWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
def setupUi(self, secondWidgetWindow):
### creating line edit to take input from user
### creating save button
self.btnSave.clicked.connect(self.saveUserInput)
def saveUserInput(self):
## saving user inputs in xml file
self.close() ## here i needs to close this window.

Answer 1

Close second widget after pressing save button:
self.secondWidgetWindow.hide()
Try it:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_secondWidgetWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.secondWidgetWindow = None
def setupUi(self, secondWidgetWindow):
self.secondWidgetWindow = secondWidgetWindow
### creating line edit to take input from user
self.line_edit = QtWidgets.QLineEdit(secondWidgetWindow)
self.line_edit.setGeometry(20, 20, 300, 20)
### creating save button
self.btnSave = QtWidgets.QPushButton('save', secondWidgetWindow)
self.btnSave.setGeometry(50, 50, 100, 50)
self.btnSave.clicked.connect(self.saveUserInput)
def saveUserInput(self):
## saving user inputs in xml file
#self.close() ## here i needs to close this window.
self.secondWidgetWindow.hide()
QtWidgets.QMessageBox.information(self, "SAVE",
"saving user inputs in xml file")
class Ui_firstWidgetWindow(QtWidgets.QMainWindow):
def __init__(self,firstWidgetWindow):
super().__init__()
self.setupUi(firstWidgetWindow)
def setupUi(self, firstWidgetWindow):
### code to create Button ###
self.btnOpenNewWidgetWindow = QtWidgets.QPushButton('OpenNewWidgetWindow', firstWidgetWindow)
self.btnOpenNewWidgetWindow.setGeometry(50, 100, 300, 50)
self.btnOpenNewWidgetWindow.clicked.connect(self.openNewWindow)
def openNewWindow(self):
self.secondWidgetWindow = QtWidgets.QWidget()
self.ui = Ui_secondWidgetWindow()
self.ui.setupUi(self.secondWidgetWindow)
self.secondWidgetWindow.show()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
firstWidgetWindow = QtWidgets.QWidget()
ui = Ui_firstWidgetWindow(firstWidgetWindow)
firstWidgetWindow.setGeometry(700, 250, 400, 200)
firstWidgetWindow.show()
sys.exit(app.exec_())