from PySide import QtCore, QtGui

class TreeItem(object):
    def __init__(self, data, parent=None):
        self.parentItem = parent
        self.itemData = data
        self.childItems = []

    def appendChild(self, item):
        self.childItems.append(item)

    def child(self, row):
        return self.childItems[row]

    def childCount(self):
        return len(self.childItems)

    def columnCount(self):
        return len(self.itemData)

    def data(self, column):
        try:
            return self.itemData[column]
        except IndexError:
            return None

    def parent(self):
        return self.parentItem

    def row(self):
        if self.parentItem:
            return self.parentItem.childItems.index(self)

        return 0


class TreeModel(QtCore.QAbstractItemModel):
    def __init__(self, data, parent=None):
        super(TreeModel, self).__init__(parent)

        self.rootItem = TreeItem(("X", "N"))
        self.setupModelData(data, self.rootItem)

    def columnCount(self, parent):
        if parent.isValid():
            return parent.internalPointer().columnCount()
        else:
            return self.rootItem.columnCount()

    def data(self, index, role):
        if not index.isValid():
            return None

        if role == QtCore.Qt.SizeHintRole:
            return QtCore.QSize(40,50)

        if role == QtCore.Qt.TextAlignmentRole and index.column() == 1:
            r = index.row()
            if r == 0:
                return QtCore.Qt.AlignRight
            elif r == 1:
                return QtCore.Qt.AlignRight | QtCore.Qt.AlignVCenter
            else:
                return QtCore.Qt.AlignBottom

        if role != QtCore.Qt.DisplayRole:
            return None

        item = index.internalPointer()

        return item.data(index.column())

    def flags(self, index):
        if not index.isValid():
            return QtCore.Qt.NoItemFlags

        return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable

    def headerData(self, section, orientation, role):
        if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
            return self.rootItem.data(section)

        return None

    def index(self, row, column, parent):
        if not self.hasIndex(row, column, parent):
            return QtCore.QModelIndex()

        if not parent.isValid():
            parentItem = self.rootItem
        else:
            parentItem = parent.internalPointer()

        childItem = parentItem.child(row)
        if childItem:
            return self.createIndex(row, column, childItem)
        else:
            return QtCore.QModelIndex()

    def parent(self, index):
        if not index.isValid():
            return QtCore.QModelIndex()

        childItem = index.internalPointer()
        parentItem = childItem.parent()

        if parentItem == self.rootItem:
            return QtCore.QModelIndex()

        return self.createIndex(parentItem.row(), 0, parentItem)

    def rowCount(self, parent):
        if parent.column() > 0:
            return 0

        if not parent.isValid():
            parentItem = self.rootItem
        else:
            parentItem = parent.internalPointer()

        return parentItem.childCount()

    def setupModelData(self, lines, parent):
        for columnData in lines:
            parent.appendChild(TreeItem(columnData, parent))


if __name__ == '__main__':

    import sys

    app = QtGui.QApplication(sys.argv)

    model = TreeModel([["a","1"],["b","2"],["c","3"]])

    view = QtGui.QTreeView()
    view.setModel(model)
    view.setWindowTitle("Simple Tree Model")
    view.show()
    sys.exit(app.exec_())