Editable QTableView and Pandas do not work properly

Question

I am trying to get a self-contained piece of example code for using pandas and QTableView while getting editable cell views.

For this I am following up to an earlier

Answer 1

It seems to work when I switch to PySide instead of PyQt4:

import sys
from PySide import QtCore, QtGui
import pandas as pd
Qt = QtCore.Qt

    class PandasModelEditable(QtCore.QAbstractTableModel):
    def __init__(self, data, parent=None):
        QtCore.QAbstractTableModel.__init__(self, parent)
        self._data = data

    def rowCount(self, parent=None):
        return len(self._data.values)

    def columnCount(self, parent=None):
        return self._data.columns.size

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if index.isValid():
            if role == QtCore.Qt.DisplayRole or role == QtCore.Qt.EditRole:
                return unicode(self._data.iloc[index.row(), index.column()])
        return None

    def headerData(self, section, orientation, role=QtCore.Qt.DisplayRole):
        if role != QtCore.Qt.DisplayRole:
            return None
        if orientation == QtCore.Qt.Horizontal:
            try:
                return '%s' % unicode(self._data.columns.tolist()[section])
            except (IndexError,):
                return unicode()
        elif orientation == QtCore.Qt.Vertical:
            try:
                return '%s' % unicode(self._data.index.tolist()[section])
            except (IndexError,):
                return unicode()

    def flags(self, index):
        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | \
               QtCore.Qt.ItemIsEditable

    def setData(self, index, value, role=QtCore.Qt.EditRole):
        if index.isValid():
            self._data.iloc[index.row(), index.column()] = value
            if self.data(index, QtCore.Qt.DisplayRole) == value:
                self.dataChanged.emit(index, index)
                return True
        return False


if __name__ == '__main__':
    application = QtGui.QApplication(sys.argv)
    view = QtGui.QTableView()
    df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=['a', 'b', 'c'], index=['x', 'y'])

    model = PandasModelEditable(df)
    view.setModel(model)

    view.show()
    sys.exit(application.exec_())