Sort a PySide.QtGui.QTreeWidget by an alpha numeric column

I would like to sort a QTreeWidget by the alpha_numeric column.

Update:

Following ekhumoro's example, I re-implemented the QTreeWidgetItem __lt__ method to use the desired natural sorting.

Relevant code:

class TreeWidgetItem(QtGui.QTreeWidgetItem):
    def __lt__(self, other):
        column = self.treeWidget().sortColumn()
        key1 = self.text(column)
        key2 = other.text(column)
        return self.natural_sort_key(key1) < self.natural_sort_key(key2)

    @staticmethod
    def natural_sort_key(key):
        regex = '(\d*\.\d+|\d+)'
        parts = re.split(regex, key)
        return tuple((e if i % 2 == 0 else float(e)) for i, e in enumerate(parts))

Updated full working example:

import sys
import re
from PySide import QtGui, QtCore

data = [
    {"name": "Apple", "alpha_numeric": "11"},
    {"name": "Apple", "alpha_numeric": "125b"},
    {"name": "Apple", "alpha_numeric": "125a"},
    {"name": "Apple", "alpha_numeric": "3"},
    {"name": "Orange", "alpha_numeric": "11"},
    {"name": "Orange", "alpha_numeric": "125b"},
    {"name": "Orange", "alpha_numeric": "125a"},
    {"name": "Orange", "alpha_numeric": "3"},
]

# re-implement the QTreeWidgetItem
class TreeWidgetItem(QtGui.QTreeWidgetItem):
    def __lt__(self, other):
        column = self.treeWidget().sortColumn()
        key1 = self.text(column)
        key2 = other.text(column)
        return self.natural_sort_key(key1) < self.natural_sort_key(key2)

    @staticmethod
    def natural_sort_key(key):
        regex = '(\d*\.\d+|\d+)'
        parts = re.split(regex, key)
        return tuple((e if i % 2 == 0 else float(e)) for i, e in enumerate(parts))


class MainWindow(QtGui.QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.resize(300, 300)
        self.table = None
        self.ui()

    def ui(self):
        # setup the table
        self.table = QtGui.QTreeWidget()
        self.table.setRootIsDecorated(False)
        self.table.setAlternatingRowColors(True)
        self.table.setSortingEnabled(True)

        # columns and widths
        column_names = ['Name', 'Alpha Numeric']
        self.table.setColumnCount(2)
        self.table.setColumnWidth(0, 150)
        self.table.setColumnWidth(1, 150)
        self.table.setHeaderLabels(column_names)

        # row data
        for row in data:
            column = TreeWidgetItem(self.table)
            column.setSizeHint(0, QtCore.QSize(30, 30))
            column.setText(0, row['name'])
            column.setText(1, row['alpha_numeric'])

        # sort
        self.table.sortByColumn(1, QtCore.Qt.AscendingOrder)
        self.table.sortByColumn(0, QtCore.Qt.AscendingOrder)

        # setup the layout
        self.setCentralWidget(self.table)


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

You can re-implement the less-than operator of your tree-widget items and use whatever algorithm you like to control sorting:

class TreeWidgetItem(QtGui.QTreeWidgetItem):
    def __lt__(self, other):
        return funky_sort_key(self.text(), other.text())

Using this method, you don't even need to sort by text - you could also sort by the item-data (or whatever).