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 __expectation_step(self):
        self.__gaussians = [ [] for _ in range(self.__amount_clusters) ]
        for index in range(self.__amount_clusters):
            self.__gaussians[index] = gaussian(self.__data, self.__means[index], self.__variances[index])