'Implement a Column sort'

def sortByColumn(self, index):

    if (self.sort_old == [None]):
        self.header_class.setSortIndicatorShown(True)
    sort_order = self.header_class.sortIndicatorOrder()
    if (not self.model().sort(index, sort_order)):
        if (len(self.sort_old) != 2):
            self.header_class.setSortIndicatorShown(False)
        else:
            self.header_class.setSortIndicator(self.sort_old[0], self.sort_old[1])
        return
    self.sort_old = [index, self.header_class.sortIndicatorOrder()]
