but all cell is updated when datachanged is emitted.

data() was called hundreds times for each cells and each roles.

what is wrong with this code ?

class TestitemTableModel(QAbstractTableModel):

def __init__(self, data):
    super(TestitemTableModel, self).__init__()
    self._data = data

def data(self, index, role):

    if role == QtCore.Qt.DisplayRole:
        value = self._data.iloc[index.row(), index.column()]
        return str(value)

    if role == QtCore.Qt.TextAlignmentRole:
        return int(QtCore.Qt.AlignCenter | QtCore.Qt.AlignVCenter)


def setData(self, index, value, role):

    if not index.isValid():
        return False

    if role == QtCore.Qt.DisplayRole:
        self._data.iloc[index.row(), index.column()] = 'WTF'
        
        self.dataChanged.emit(index, index)

        return True

    return QAbstractTableModel.setData(self,index,value,role)

def rowCount(self, index):
    return self._data.shape[0]

def columnCount(self, index):
    return self._data.shape[1]

def headerData(self, section, orientation, role):
    if role == QtCore.Qt.DisplayRole:
        if orientation == QtCore.Qt.Horizontal:
            return str(self._data.columns[section])
        
        if orientation == QtCore.Qt.Vertical:
            return str(self._data.index[section])