sort a column with setCellWidget in QTableWidget

Question

I am trying to sort a column which has progressbar in it. I want column to be sorted by progressbar value. Any help will be much appreciated

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


class Example(QMainWindow):

    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):

        self.tablew = Table(self)
        self.setCentralWidget(self.tablew)

        self.setGeometry(300, 300, 300, 200)
        self.show()


class ProgressBar(QProgressBar):

    def __init__(self, value, parent=None):
        QProgressBar.__init__(self)
        self.setMinimum(1)
        self.setMaximum(5.0)
        self.setValue(value)
        self.setFormat('{0:.5f}'.format(value))
        style = ''' QProgressBar{max-height: 15px;text-align: center;}'''
        self.setStyleSheet(style)


class Table(QTableWidget):

    def __init__(self,   parent=None):
        QTableWidget.__init__(self)
        self.setColumnCount(2)
        self.setHorizontalHeaderLabels(['id', 'status'])
        header = self.horizontalHeader()
        header.setResizeMode(QHeaderView.Stretch)
        self.setSortingEnabled(True)
        self.loadData()
        #

    def loadData(self):
        #
        tableData = [[89, 4.8], [99, 3.9], [101, 2.6], [105, 4]]
        #
        self.setRowCount(len(tableData))
        #
        for index, value in enumerate(tableData):
            # column1
            item = QTableWidgetItem()
            item.setData(Qt.DisplayRole, value[0])
            self.setItem(index, 0, item)
            # column2
            self.setCellWidget(index, 1, ProgressBar(value[1]))
        #


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

UPDATE: Based on answer from @ekhumoro Below is the complete code but somehow it doest sort correctly. Screenshot attached after sorting column manually

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


class Example(QMainWindow):

    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):

        self.tablew = Table(self)
        self.setCentralWidget(self.tablew)

        self.setGeometry(300, 300, 300, 200)
        self.show()


class ProgressBar(QProgressBar):

    def __init__(self, value, parent=None):
        QProgressBar.__init__(self)
        self.setMinimum(1)
        self.setMaximum(5.0)
        self.setValue(value)
        self.setFormat('{0:.5f}'.format(value))
        style = ''' QProgressBar{max-height: 15px;text-align: center;}'''
        self.setStyleSheet(style)


class Table(QTableWidget):

    def __init__(self,   parent=None):
        QTableWidget.__init__(self)
        self.setColumnCount(2)
        self.setHorizontalHeaderLabels(['id', 'status'])
        header = self.horizontalHeader()
        header.setResizeMode(QHeaderView.Stretch)
        self.setSortingEnabled(True)
        self.loadData()
        #

    def loadData(self):
        #
        tableData = [[89, 4.8], [99, 3.9], [101, 2.6], [105, 4]]
        #
        self.setRowCount(len(tableData))
        #
        for index, value in enumerate(tableData):
            # column1
            item = QTableWidgetItem()
            item.setData(Qt.DisplayRole, value[0])
            self.setItem(index, 0, item)
            # column2
            item = ProgressWidgetItem()
            self.setItem(index, 1, item)
            item.updateValue(value[1])
            progress = ProgressBar(value[1])
            self.setCellWidget(index, 1, progress)
            progress.valueChanged.connect(item.updateValue)
        self.sortItems(1, Qt.DescendingOrder)


class ProgressWidgetItem(QTableWidgetItem):

    def __lt__(self, other):
        return self.data(Qt.UserRole) < other.data(Qt.UserRole)

    def updateValue(self, value):
        self.setData(Qt.UserRole, value)


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

Answer 1

You can subclass QTableWidgetItem and reimplement __lt__, and then add blank items to the progress bar column:

            # column2
            item = ProgressWidgetItem()
            self.setItem(index, 1, item)
            item.updateValue(value[1])
            progress = ProgressBar(value[1])
            self.setCellWidget(index, 1, progress)
            progress.valueChanged.connect(item.updateValue)
        self.sortItems(1, Qt.DescendingOrder)


class ProgressWidgetItem(QTableWidgetItem):
    def __lt__(self, other):
        # python 3
        # return self.data(Qt.UserRole) < other.data(Qt.UserRole)
        # python 2
        return (self.data(Qt.UserRole).toPyObject() <
                other.data(Qt.UserRole).toPyObject())

    def updateValue(self, value):
        self.setData(Qt.UserRole, value)

PS:

The implementation of __lt__ is different for Python 2 vs Python 3, because, by default, the latter will return normal Python types rather than QVariant and QString. It is possible to directly test whether two QVariant objects are equal, but not whether one is less than the other (even if they contain values of the same type).

In Python 2, you can eliminate QVariant and QString by putting the following code before the first PyQt imports in your application:

import sip
sip.setapi('QString', 2)
sip.setapi('QVariant', 2)

This will make the behaviour the same as Python 3, and means you never have to use ugly code like variant.toPyObject() or str(qtstring).