如何在QListWidget中筛选项目

from PyQt5.QtWidgets import QApplication, QListWidget, QListWidgetItem, QLineEdit, QVBoxLayout, QWidget

class FilterWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.list_widget = QListWidget()
        self.filter_input = QLineEdit()
        self.filter_input.textChanged.connect(self.filter_items)

        layout = QVBoxLayout()
        layout.addWidget(self.filter_input)
        layout.addWidget(self.list_widget)
        self.setLayout(layout)

        self.populate_list()

    def populate_list(self):
        items = ['Apple', 'Banana', 'Orange', 'Grape', 'Watermelon']
        for item in items:
            list_item = QListWidgetItem(item)
            self.list_widget.addItem(list_item)

    def filter_items(self):
        filter_text = self.filter_input.text().lower()
        for i in range(self.list_widget.count()):
            item = self.list_widget.item(i)
            if filter_text in item.text().lower():
                item.setHidden(False)
            else:
                item.setHidden(True)

if __name__ == '__main__':
    app = QApplication([])
    window = FilterWidget()
    window.show()
    app.exec_()