PySide2 QTreeView with Custom QSortFilterProxyModel

from Qt import QtWidgets, QtCore


class CustomProxyModel(QtCore.QSortFilterProxyModel):
    def __init__(self):
        super(CustomProxyModel, self).__init__()
        # self.setDynamicSortFilter(True)

    def rowCount(self, index):
        model_index = self.mapToSource(index)
        if not model_index.isValid():
            return 0
        new_rc = self.sourceModel().rowCount(model_index) + 1
        # self.insertRows(0)
        return new_rc

    def insertRows(self, position, rows=1, parent=QtCore.QModelIndex()):
        self.beginInsertRows(parent, position, position + rows - 1)
        for row in range(rows):
            self.insertRows(position, row, parent)
            self.setData(parent, "AWESOME")
            print 'AWESOME VIRTUAL ROW'
        self.endInsertRows()
        return True

class MyWindow(QtWidgets.QDialog):
    k_base_path = '/home/harshad/skin_weights/'

    def __init__(self):
        super(MyWindow, self).__init__()

        self.create_widgets()
        self.create_connections()

    def create_widgets(self):
        # Layout
        layout = QtWidgets.QVBoxLayout()
        self.setLayout(layout)

        # TreeView
        self.view = QtWidgets.QTreeView()
        layout.addWidget(self.view)

        # Selection model
        self.selection_model = QtCore.QItemSelectionModel()
        self.view.setSelectionModel(self.selection_model)

        # Model
        self.model = QtWidgets.QFileSystemModel()
        self.model.setRootPath(QtCore.QDir.rootPath())

        # Set Model Filters
        self.model.setNameFilterDisables(False)
        self.model.setNameFilters(["*.xml"])

        # Proxy
        self.proxy = CustomProxyModel()
        self.proxy.setSourceModel(self.model)
        self.proxy.sort(0, QtCore.Qt.AscendingOrder)

        # View--Proxy--Model
        self.view.setModel(self.proxy)
        self.model_index = self.model.index(self.k_base_path)
        self.proxy_index = self.proxy.mapFromSource(self.model_index)
        self.view.setRootIndex(self.proxy_index)

        # Filters
        self.view.hideColumn(1)
        self.view.hideColumn(2)
        self.view.setSortingEnabled(True)
        self.view.setAlternatingRowColors(True)
        # self.view.sortByColumn(0, QtCore.Qt.AscendingOrder)
        self.view.header().setStretchLastSection(False)
        self.view.header().resizeSection(0, 200)
        # self.view.header().setSectionResizeMode(
        #     0, QtWidgets.QHeaderView.Stretch)
        # # self.view.header().setSectionResizeMode(
        # #     1, QtWidgets.QHeaderView.ResizeToContents)
        # self.view.header().setSectionResizeMode(
        #     3, QtWidgets.QHeaderView.ResizeToContents)

        # self.proxy.setData(self.proxy.index(0,1), "AWESOME")

    def create_connections(self):
        self.view.selectionModel().selectionChanged.connect(
            self.on_selection_change)

    def on_selection_change(self):
        view_index = self.view.selectionModel().selectedIndexes()[0]
        proxy_index = self.proxy.mapToSource(view_index)
        item_name = self.model.fileName(proxy_index)
        print item_name

if __name__ == "__main__":
    try:
        win.close()
        win.deleteLater()
    except Exception:
        pass

    win = MyWindow()
    win.show()