Qtablewidget- Automatic Formula Driven Cell

Is it possible to make one cell a formula driven cell and have it update automatically? Similar to Excel. For example, I want user to fill out two cells, and then a third cell will

Solution 1:

An elegant solution is to create a custom class that inherits from QTableWidget, where you connect the itemChanged signal, this is issued each time the cell changes value (this returns the changed item but will use it only to verify that the default columns are the ones have been changed).

In addition to not having problems that the user places different values to a floating we will use a QDoubleValidator, for that we create a custom QItemDelegate.

classFloatDelegate(QItemDelegate):
    def__init__(self, _from, _to, _n_decimals, parent=None):
        QItemDelegate.__init__(self, parent=parent)
        self._from = _from
        self._to = _to
        self._n_decimals = _n_decimals

    defcreateEditor(self, parent, option, index):
        lineEdit = QLineEdit(parent)
        _n_decimals = 2
        validator = QDoubleValidator(self._from, self._to, self._n_decimals, lineEdit)
        lineEdit.setValidator(validator)
        return lineEdit


classCustomTableWidget(QTableWidget):
    _from = 0
    _to = 10**5
    _n_decimals = 2def__init__(self, i,  parent=None):
        QTableWidget.__init__(self, 5, 3, parent=parent)
        self.setItemDelegate(FloatDelegate(self._from, self._to, self._n_decimals, self))
        self.setHorizontalHeaderLabels(['OEM (Case {})'.format(i+1), 'ZVI (Case {})'.format (i+1), 'Improvement % '])
        self.setVerticalHeaderLabels(['Flow (MMSCFD)', 'HP', 'Specific Power (HP/MMSCFD)', 'Discharge Temp (F)', ''])
        self.setFixedSize(QSize(480, 180))
        self.itemChanged.connect(self.onItemChanged)

    defonItemChanged(self, item):
        # items (2, 0) = (1, 0) / (0, 0)if item.column() == 0and (item.row() == 0or item.row()==1):
            num = self.item(1, 0)
            den = self.item(0, 0)
            if num and den:
                resp = float(num.data(Qt.DisplayRole))/float(den.data(Qt.DisplayRole))
                rest_string = str(round(resp, self._n_decimals))
                it = QTableWidgetItem(rest_string, QTableWidgetItem.Type)
                self.setItem(2, 0, it)

Example:

class Widget(QWidget):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent=parent)
        self.setLayout(QGridLayout())
        for i in range(2):
            self.layout().addWidget(CustomTableWidget(i))

if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    window = Widget()
    window.show()
    sys.exit(app.exec_())

In your case:

self.tableWidget = {}
for i inrange(int(self.numberLine.text())):
    self.tableWidget[i] = CustomTableWidget(i)
    self.gridLayout_14.addWidget(self.tableWidget[i])

Another option instead of using validators, we can change the QLineEdit to QDoubleSpinBox.

defcreateEditor(self, parent, option, index):
    w = QDoubleSpinBox(parent)
    _n_decimals = 2
    w.setMinimum(self._from)
    w.setMaximum(self._to)
    w.setDecimals(self._n_decimals)
    return w

Solution 2:

Connect the cell to the other cells EditingFinished signal