Sort a QTreeWidgetItem by a data value?

Question

Is it possible to sort a PyQt QTreeWidget by a QTreeWidgetItem's data column?

For example, I've got a list of directories I want to sort by size on disk displaying in the QTreeWidget, but instead of displaying the results (in bytes) I use a method to convert the directory size to megabytes/gigabytes, but still be able to sort the items by the actual value, which I've stored in the QTreeWidgetItem's data slot.

score 6 · Answer 1 · answered Aug 01 '12 at 17:56

Yea, I've run into this a lot. I've always thought that theoretically doing something like:

item = QTreeWidgetItem()
item.setData(0, Qt.EditRole, QVariant(1024))
item.setData(0, Qt.DisplayRole, '1 Kb')

SHOULD work...unfortunately it does not. The only real way to get it to work is to subclass the QTreeWidgetItem and either store your sort information in its own way, or use the Qt.UserRole vs. EditRole or DisplayRole:

class MyTreeWidgetItem(QTreeWidgetItem):
    def __lt__( self, other ):
        if ( not isinstance(other, MyTreeWidgetItem) ):
            return super(MyTreeWidgetItem, self).__lt__(other)

        tree = self.treeWidget()
        if ( not tree ):
            column = 0
        else:
            column = tree.sortColumn()

        return self.sortData(column) < other.sortData(column)

    def __init__( self, *args ):
        super(MyTreeWidgetItem, self).__init__(*args)
        self._sortData = {}

    def sortData( self, column ):
        return self._sortData.get(column, self.text(column))

    def setSortData( self, column, data ):
        self._sortData[column] = data

So, using it in this case would be similar to before, but actually allow for sorting via custom data:

item = MyTreeWidgetItem()
item.setSortData(0, 1024)
item.setText(0, '1 kb')01

Sort a QTreeWidgetItem by a data value?

1 Answers1