Pyqt how to get QTableWidget item object whose text is empty

Question

I have 3*3 tablewidget,but items' text is empty

self.tab = QtGui.QTableWidget() 
self.tab.setRowCount(3)
self.tab.setColumnCount(3)
self.tab.itemSelectionChanged.connect(self.fuc)

I have a fuction :I click a item ,so I can use QFileDialog to get my file path,then file path is shown in my item .

     def fuc(self):
        itemClicked = self.sender()
        index = self.tab.indexAt(itemClicked.pos())
        filename = QtGui.QFileDialog.getOpenFileName(self, 'OpenFile')
        row = index.row()
        col = index.column()
        self.tab.item(row, col).setText(filename)

But there is an error AttributeError: 'NoneType' object has no attribute 'setText' .I find if item's text is empty ,I can't get item object.The item is None .

Answer 1

It's not just that the item text is empty, it's that the item doesn't even have a text property yet. The short answer is to try/catch (check out all the answers to this question )

def _clickedCell(self, item):
    print(type(item))
    try:
        self.text_label.setText(self.table.item(item.row(), item.column()).text())
    except AttributeError:
        self.text_label.setText('Cell did not have a text property')
    except:
        self.text_label.setText('Something else went wrong')

But something else surprised me - the item passed to the _clickedCell handler is not exactly the QTableWidgetItem defined, even when it is defined. I've added some print debugging right before the same try/catch in the short answer.

Here's a smallish app that sets only some QTableWidget item text values and can display a clicked cell text value, or handle the missing text property:

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QHeaderView, QFrame,\
                        QLabel, QTableWidget, \
                        QTableWidgetItem, QVBoxLayout, QHBoxLayout

class TableWidget(QTableWidget):
    def __init__(self):
        super().__init__(2,2)
        self.setHorizontalHeaderLabels(['Text Set', 'Text Not Set'])
        self.setItem(0, 0,  QTableWidgetItem("dummy text"))
        self.setItem(1, 0,  QTableWidgetItem(""))
        self.horizontalHeader().setSectionResizeMode(QHeaderView.Fixed)





class AppDemo(QWidget):
    def __init__(self):
        super().__init__()

        mainLayout = QHBoxLayout()
        self.table = TableWidget()
        self.table.clicked.connect(self._clickedCell)
        mainLayout.addWidget(self.table)
    
        buttonLayout = QVBoxLayout()

        self.text_label = QLabel('Initialized value')
        self.text_label.setFrameStyle(QFrame.Panel)
        self.text_label.setMinimumWidth(70)
        self.text_label.setWordWrap(True)
        buttonLayout.addWidget(self.text_label)

        mainLayout.addLayout(buttonLayout)
        self.setLayout(mainLayout)

    def _clickedCell(self, item):
        print(item.row(), item.column())
        print(type(item))
        print(type(self.table.item(item.row(), item.column())))
     
        try:
            self.text_label.setText(self.table.item(
                  item.row(), item.column()).text())
        except AttributeError:
            self.text_label.setText('AttributeError: Cell had no text property')
        except:
            self.text_label.setText('Something else went wrong')
        


app = QApplication(sys.argv)
demo = AppDemo()
demo.show()
sys.exit(app.exec_())

# from https://learndataanalysis.org/add-copy-remove-rows-on-a-table-widget-pyqt5-tutorial/