PyQt: Adding rows to QTableView using QAbstractTableModel

Question

I am super new to Qt programming. I am trying to make a simple table that can have rows added by clicking a button. I can implement the table fine but can't seem to get the updated data to show on the table. I believe my problem stems from the fact that I can't seem to properly call any sort of "change data" method using the button. I've tried several different solutions online all of which have lead to 4 year old, dead-end posts. What I have so far is the basic structure, I just can't figure out how to make the table update with new data.

This is the basic view

I have set up with some test data.

In the final implementation, the table will start empty and I would like to append rows and have them displayed in the table view.

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class MyWindow(QWidget):
    def __init__(self):
        QWidget.__init__(self)

        # create table
        self.get_table_data()
        self.table = self.createTable()

        # layout
        self.layout = QVBoxLayout()

        self.testButton = QPushButton("test")
        self.connect(self.testButton, SIGNAL("released()"), self.test)        

        self.layout.addWidget(self.testButton)
        self.layout.addWidget(self.table)
        self.setLayout(self.layout)

    def get_table_data(self):
        self.tabledata = [[1234567890,2,3,4,5],
                          [6,7,8,9,10],
                          [11,12,13,14,15],
                          [16,17,18,19,20]]

    def createTable(self):
        # create the view
        tv = QTableView()

        # set the table model
        header = ['col_0', 'col_1', 'col_2', 'col_3', 'col_4']
        tablemodel = MyTableModel(self.tabledata, header, self)
        tv.setModel(tablemodel)

        # set the minimum size
        tv.setMinimumSize(400, 300)

        # hide grid
        tv.setShowGrid(False)

        # hide vertical header
        vh = tv.verticalHeader()
        vh.setVisible(False)

        # set horizontal header properties
        hh = tv.horizontalHeader()
        hh.setStretchLastSection(True)

        # set column width to fit contents
        tv.resizeColumnsToContents()

        # set row height
        tv.resizeRowsToContents()

        # enable sorting
        tv.setSortingEnabled(False)

        return tv

    def test(self):
        self.tabledata.append([1,1,1,1,1])
        self.emit(SIGNAL('dataChanged()'))
        print 'success'

class MyTableModel(QAbstractTableModel):
    def __init__(self, datain, headerdata, parent=None):
        """
        Args:
            datain: a list of lists\n
            headerdata: a list of strings
        """
        QAbstractTableModel.__init__(self, parent)
        self.arraydata = datain
        self.headerdata = headerdata

    def rowCount(self, parent):
        return len(self.arraydata)

    def columnCount(self, parent):
        if len(self.arraydata) > 0: 
            return len(self.arraydata[0]) 
        return 0

    def data(self, index, role):
        if not index.isValid():
            return QVariant()
        elif role != Qt.DisplayRole:
            return QVariant()
        return QVariant(self.arraydata[index.row()][index.column()])

    def setData(self, index, value, role):
        pass         # not sure what to put here

    def headerData(self, col, orientation, role):
        if orientation == Qt.Horizontal and role == Qt.DisplayRole:
            return QVariant(self.headerdata[col])
        return QVariant()

    def sort(self, Ncol, order):
        """
        Sort table by given column number.
        """
        self.emit(SIGNAL("layoutAboutToBeChanged()"))
        self.arraydata = sorted(self.arraydata, key=operator.itemgetter(Ncol))       
        if order == Qt.DescendingOrder:
            self.arraydata.reverse()
        self.emit(SIGNAL("layoutChanged()"))

if __name__ == "__main__":
    app = QApplication(sys.argv)
    w = MyWindow()
    w.show()
    sys.exit(app.exec_())

Answer 1

When the underlying data of the model changes, the model should emit either layoutChanged or layoutAboutToBeChanged, so that view updates properly (there's also dataChanged, if you want to update a specific range of cells).

So you just need something like this:

    def test(self):
        self.tabledata.append([1,1,1,1,1])
        self.table.model().layoutChanged.emit()
        print 'success'