ड्रिल डाउन QListWidget

QListWidget की जानकारी को फिर से बनाने के बजाय आप QListView के साथ एक पेड़ जैसी संरचना वाले मॉडल का उपयोग कर सकते हैं और दृश्य के रूटइंडेक्स को बदल सकते हैं:

import sys

from PyQt5 import QtCore, QtGui, QtWidgets

data = {
    "item1": {
        "item 1-1": ["item 1-1-1", "item 1-1-2", "item 1-1-3"],
        "item 1-2": ["item 1-2-1", "item 1-2-2", "item 1-2-3"],
        "item 1-3": ["item 1-3-1", "item 1-3-2", "item 1-3-3"],
    },
    "item2": {
        "item 2-1": ["item 2-1-1", "item 2-1-2", "item 2-1-3"],
        "item 2-2": ["item 2-2-1", "item 2-2-2", "item 2-2-3"],
        "item 2-3": ["item 2-3-1", "item 2-3-2", "item 2-3-3"],
    },
    "item3": {
        "item 3-1": ["item 3-1-1", "item 3-1-2", "item 3-1-3"],
        "item 3-2": ["item 3-2-1", "item 3-2-2", "item 3-2-3"],
        "item 3-3": ["item 3-3-1", "item 3-3-2", "item 3-3-3"],
    },
}

# https://stackoverflow.com/a/53747062
def fill_model_from_json(parent, d):
    if isinstance(d, dict):
        for k, v in d.items():
            child = QtGui.QStandardItem(str(k))
            parent.appendRow(child)
            fill_model_from_json(child, v)
    elif isinstance(d, list):
        for v in d:
            fill_model_from_json(parent, v)
    else:
        parent.appendRow(QtGui.QStandardItem(str(d)))


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.view = QtWidgets.QListView()
        self.button = QtWidgets.QPushButton("Up")

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(self.view)
        lay.addWidget(self.button)

        self.button.setEnabled(False)

        self.view.clicked.connect(self.handle_view_clicked)
        self.button.clicked.connect(self.handle_button_clicked)

        model = QtGui.QStandardItemModel()
        self.view.setModel(model)

        fill_model_from_json(model.invisibleRootItem(), data)

    @QtCore.pyqtSlot(QtCore.QModelIndex)
    def handle_view_clicked(self, index):
        if self.view.model().hasChildren(index):
            self.view.setRootIndex(index)
        self.button.setEnabled(self.view.rootIndex().isValid())

    @QtCore.pyqtSlot()
    def handle_button_clicked(self):
        self.view.setRootIndex(self.view.rootIndex().parent())
        self.button.setEnabled(self.view.rootIndex().isValid())


if __name__ == "__main__":

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())