QListView with CustomWIdget using QStyledItemDelegate

I'm trying to create a QListView with QStyledItemDelegate to show data more organizing way.

I gone through this site, and its all in C++, and I have no idea about it, guessing from the syntax and calls which has been used in the post, I tried my way to achieve it, but I had not luck. Can someone please help me out with this?

import sys, os

from PyQt4 import QtGui, QtCore


class ListView(QtGui.QListView):
    def __init__(self, parent=None):
        super(ListView, self).__init__(parent)

        self._model = None
        self._data = [
                        [
                        'Header: King Arthur',
                        'Project: TBN',
                        'Asset: arthur',
                        'Task name: Design doc',
                        'Start Date: Today',
                        'End Date: Next Monday'
                        ]
                    ]
        self.set_model()
        item_delegate = ItemDelegate()
        self.setItemDelegate(item_delegate)
        self.openPersistentEditor(self._model.createIndex(0, 0))

    def set_model(self):
        self._model = ListModel(self._data, parent=self)
        self.setModel(self._model)


class ListModel(QtCore.QAbstractItemModel):
    def __init__(self, data=[], parent=None):
        super(ListModel, self).__init__(parent)
        self._data = data

    def rowCount(self, *arg):
        return 1 

    def columnCount(self, *arg):
        return len(self._data)

    def data(self, index, role):
        row = index.row()
        column = index.column()

        if role == QtCore.Qt.DisplayRole:
            return QtCore.QVariant(' | '.join(self._data[column]))

        return QtCore.QVariant()

    def index(self, row, column, parent):
        return self.createIndex(row, column)

    def parent(self, index):
        item = index.internalPointer()
        if item:
            return item.getParent()
        else:
            item = self.createIndex(index.row(), index.column()).internalPointer()
            if item:
                return item.getParent()

        return QtCore.QModelIndex()

class ItemDelegate(QtGui.QStyledItemDelegate):
    def createEditor(self, parent, option, index):
        item_data = str(index.data().toString())
        editor = Widget(item_data.split('|'), parent=parent)
        return editor

    def updateEditorGeometry(self, editor, option, index):
        editor.setGeometry(option.rect) 

class Widget(QtGui.QWidget):
    def __init__(self, widget_data=[], parent=None):
        super(Widget, self).__init__(parent)

        vbox = QtGui.QVBoxLayout(self)
        key_font = QtGui.QFont()
        key_font.setWeight(QtGui.QFont.Bold)
        val_font = QtGui.QFont()
        val_font.setWeight(QtGui.QFont.Normal)

        for each_data in widget_data:
            hbox = QtGui.QHBoxLayout()
            key, value = each_data.split(':')
            key_text = QtGui.QLabel(self)
            val_text = QtGui.QLabel(self)

            key_text.setToolTip('Key: %s' % key)
            val_text.setToolTip('Value: %s' % value)

            key_text.setText(key)
            val_text.setText(value)

            key_text.setFont(key_font)
            val_text.setFont(val_font)

            hbox.addWidget(key_text)
            hbox.addWidget(val_text)
            # vbox.addLayout(hbox)


if __name__ == '__main__':
    qapp = QtGui.QApplication([])
    app = ListView()
    app.show()
    sys.exit(qapp.exec_())