Pyqt5 method to close or delete the widget and setup it again on command - python-3.x

Question

I have created short application with Pyqt5 designer:
Here is the code:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_Form(object):
def setupUi(self, Form):
Form.setObjectName("Form")
Form.resize(752, 674)
self.formLayout_2 = QtWidgets.QFormLayout(Form)
self.formLayout_2.setObjectName("formLayout_2")
self.formLayout = QtWidgets.QFormLayout()
self.formLayout.setObjectName("formLayout")
self.formLayout_2.setLayout(0, QtWidgets.QFormLayout.LabelRole, self.formLayout)
self.pushButton = QtWidgets.QPushButton(Form)
self.pushButton.setObjectName("pushButton")
self.formLayout_2.setWidget(0, QtWidgets.QFormLayout.FieldRole, self.pushButton)
self.widget = QtWidgets.QWidget(Form)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(1)
sizePolicy.setHeightForWidth(self.widget.sizePolicy().hasHeightForWidth())
self.widget.setSizePolicy(sizePolicy)
self.widget.setStyleSheet("background-color:white;")
self.widget.setObjectName("widget")
self.formLayout_2.setWidget(2, QtWidgets.QFormLayout.FieldRole, self.widget)
self.pushButton_2 = QtWidgets.QPushButton(Form)
self.pushButton_2.setObjectName("pushButton_2")
self.formLayout_2.setWidget(1, QtWidgets.QFormLayout.FieldRole, self.pushButton_2)
self.retranslateUi(Form)
QtCore.QMetaObject.connectSlotsByName(Form)
def retranslateUi(self, Form):
_translate = QtCore.QCoreApplication.translate
Form.setWindowTitle(_translate("Form", "Form"))
self.pushButton.setText(_translate("Form", "Letters"))
self.pushButton_2.setText(_translate("Form", "Numbers"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
Form = QtWidgets.QWidget()
ui = Ui_Form()
ui.setupUi(Form)
Form.show()
sys.exit(app.exec_())
This script is connected to appexe script(dialog):
import sys
from PyQt5 import QtWidgets, QtCore, QtGui
import string
from functools import partial
from setup_test import Ui_Form
from PyQt5.QtWidgets import QWidget, QGridLayout, QPushButton, QApplication
class myprog(Ui_Form):
def __init__ (self, dialog):
Ui_Form.__init__(self)
self.setupUi(dialog)
self.symbols = [string.ascii_lowercase, string.digits]
self.buttons = [self.pushButton, self.pushButton_2]
for i,v in enumerate(self.buttons):
self.buttons[i].clicked.connect(partial(self.application, i))
def application(self, i):
self.grid1 = QGridLayout(self.widget)
names = [x for x in self.symbols[i]]
positions = [(j,d) for j in range(7) for d in range(6)]
for a,b in zip(positions, names):
button = QPushButton(b)
self.grid1.addWidget(button, *a)
print(self.grid1.count())
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
dialog = QtWidgets.QDialog()
appexe = myprog(dialog)
dialog.show()
sys.exit(app.exec_())
I am new to Pyqt5. The basic idea is: whenever you click the button 'Letters' or button 'Numbers', the widget below should layout all the sysmbols within Letters or buttons.
If you do execute the appexe script, you can see, it works for the first try. (Please ignore the visual design). I am happy with the result. When button is pressed, it shows the buttons in grid(widget).
The problem I am facing is, how to clear the grid and it's widget when other button is hit > and display the new grid, new widgets.
If you look close, there is also a print statement:
print(self.grid1.count())
When I am in application and i am clicking letter and number button, it tells me how many widgets are within grid, however I just can't find a way how to display the new setup.
I would appreciate your help and your ideas. Thank you.

Answer 1

There are a number of different ways to remove a layout and its child widgets. However, the only one that seems to work properly with your particular example, is this one:
def application(self, i):
layout = self.widget.layout()
if layout is not None:
QWidget().setLayout(layout)
...
This works because setting the layout on a different widget will automatically re-parent that layout and all its children. Then when the temporary parent widget is immediately garbage-collected, Qt will automatically delete all its children as well.