[PyQt] Item data on QTreeView

[Diego]

Hi,

I have a QTreeView widget that displays one Message per row. It also
has several columns, each of which displays one Message's attribute.
The tree's model is a QStandardItemModel that I populate this way:

for m in messages:
    items = []
    it = QStandardItem()
    it.message = m     # (1) See here
    it.setData(m.headers['Subject'], Qt.DisplayRole)
    it.setCheckable(False)
    items.append(it)

    it = QStandardItem()
    it.message = m    # (2) See here
    it.setData(m.headers['From'], Qt.DisplayRole)
    items.append(it)

    it = QStandardItem()
    it.message = m    # (3) See here
    it.setData(m.headers['Date'], Qt.DisplayRole)
    items.append(it)

    tree_view.model().appendRow(items)


When a row is selected in the QTreeView, I need to be able to access
the object whose attributes are being displayed in that row. I don't
know how to properly do that, and the only thing that worked for me is
to store the original object in each and every item I create, as in
(1), (2) and (3) in the code snippet above. It appears to me as a very
inefficient way of solving this problem and I think there must be a
much better solution for it.

So my question is: how do I store the original Message object in every
row in order to get access to it when the user selects that row?

Thanks in advance,
Diego