def onShortcutUnindentWithBackspace(self):
        """Backspace pressed, unindent
        """
        assert self._qpart.textBeforeCursor().endswith(self.text())

        charsToRemove = len(self._qpart.textBeforeCursor()) % len(self.text())
        if charsToRemove == 0:
            charsToRemove = len(self.text())

        cursor = self._qpart.textCursor()
        cursor.setPosition(cursor.position() - charsToRemove, QTextCursor.KeepAnchor)
        cursor.removeSelectedText()
def main():
    # Contingency Table from Wilks (2011) Table 8.3
    table = np.array([[50, 91, 71],
                      [47, 2364, 170],
                      [54, 205, 3288]])
    mct = MulticlassContingencyTable(table, n_classes=table.shape[0],
                                     class_names=np.arange(table.shape[0]).astype(str))
    print(mct.peirce_skill_score())
    print(mct.gerrity_score())