PROJECT.py

from PyQt5.QtWidgets import QApplication, QMainWindow, QListWidgetItem
from PyQt5.uic import loadUi
import sys
from qtconsole.qt import QtCore

class Main(QMainWindow):
    def __init__(self):
        super(Main, self).__init__()
        loadUi("main.ui", self)
        todos = ["Kerjakan Projek", "Kerjakan PR", "Cuci mobil", "Ambil jemuran"]
        for todo in todos:
            item = QListWidgetItem(todo)
            item.setFlags(item.flags() | QtCore.Qt.IterIsUserCHeckable)
            item.setCheckState(QtCore.Qt.Unchecked)
            self.todo_listWidget.addItem(item)
        self.ToggleAllButton.clicked.connect(self.toggle_all)

    def toggle_all(self):
        for i in range(self.todo_listWidget.count()):
            item = self.todo_listWidget.item(i)
            if item.checkState() == QtCore.Qt.Checked:
                item.setCheckState(QtCore.Qt.Checked)
            else:
                item.setCheckState(QtCore.Qt.Checked)
                

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = Main()
    window.show()
    app.exec_()