Replace % formatting in examples by f-strings

As drive-by, Fix fortune server, addressbook and dombookmarks examples to work.

Task-number: PYSIDE-1112
Change-Id: I8ef7759ed56aeb7157cf2222bee9b6481973112a
Reviewed-by: Christian Tismer <tismer@stackless.com>

30 files changed, 124 insertions, 104 deletions

diff --git a/examples/network/blockingfortuneclient/blockingfortuneclient.py b/examples/network/blockingfortuneclient/blockingfortuneclient.py
index 4ee0ce622..536110d4e 100644
--- a/examples/network/blockingfortuneclient/blockingfortuneclient.py
+++ b/examples/network/blockingfortuneclient/blockingfortuneclient.py
@@ -205,7 +205,7 @@ class BlockingClient(QWidget):
                     "and port settings are correct.")
         else:
             QMessageBox.information(self, "Blocking Fortune Client",
-                    "The following error occurred: %s." % message)
+                    f"The following error occurred: {message}.")
 
         self.getFortuneButton.setEnabled(True)
 
diff --git a/examples/network/fortuneclient/fortuneclient.py b/examples/network/fortuneclient/fortuneclient.py
index 99ca41b0e..2e6d6d559 100644
--- a/examples/network/fortuneclient/fortuneclient.py
+++ b/examples/network/fortuneclient/fortuneclient.py
@@ -118,7 +118,6 @@ class Client(QtWidgets.QDialog):
             return
 
         nextFortune = instr.readString()
-        nextFortune = str(nextFortune, encoding='ascii')
 
         if nextFortune == self.currentFortune:
             QtCore.QTimer.singleShot(0, self.requestNewFortune)
@@ -141,8 +140,9 @@ class Client(QtWidgets.QDialog):
                     "fortune server is running, and check that the host name "
                     "and port settings are correct.")
         else:
+            reason = self.tcpSocket.errorString()
             QtWidgets.QMessageBox.information(self, "Fortune Client",
-                    "The following error occurred: %s." % self.tcpSocket.errorString())
+                    f"The following error occurred: {reason}.")
 
         self.getFortuneButton.setEnabled(True)
 
diff --git a/examples/network/fortuneserver/fortuneserver.py b/examples/network/fortuneserver/fortuneserver.py
index 7b8f05a32..e3087f1c1 100644
--- a/examples/network/fortuneserver/fortuneserver.py
+++ b/examples/network/fortuneserver/fortuneserver.py
@@ -52,18 +52,20 @@ class Server(QtWidgets.QDialog):
         super(Server, self).__init__(parent)
 
         statusLabel = QtWidgets.QLabel()
+        statusLabel.setTextInteractionFlags(QtCore.Qt.TextBrowserInteraction)
         quitButton = QtWidgets.QPushButton("Quit")
         quitButton.setAutoDefault(False)
 
         self.tcpServer = QtNetwork.QTcpServer(self)
         if not self.tcpServer.listen():
+            reason = self.tcpServer.errorString()
             QtWidgets.QMessageBox.critical(self, "Fortune Server",
-                    "Unable to start the server: %s." % self.tcpServer.errorString())
+                    f"Unable to start the server: {reason}.")
             self.close()
             return
-
-        statusLabel.setText("The server is running on port %d.\nRun the "
-                "Fortune Client example now." % self.tcpServer.serverPort())
+        port = self.tcpServer.serverPort()
+        statusLabel.setText(f"The server is running on port {port}.\nRun the "
+                "Fortune Client example now.")
 
         self.fortunes = (
                 "You've been leading a dog's life. Stay off the furniture.",
diff --git a/examples/network/threadedfortuneserver/threadedfortuneserver.py b/examples/network/threadedfortuneserver/threadedfortuneserver.py
index 839a2a57e..deb993b71 100644
--- a/examples/network/threadedfortuneserver/threadedfortuneserver.py
+++ b/examples/network/threadedfortuneserver/threadedfortuneserver.py
@@ -111,8 +111,9 @@ class Dialog(QDialog):
         quitButton.setAutoDefault(False)
 
         if not self.server.listen():
+            reason = self.server.errorString()
             QMessageBox.critical(self, "Threaded Fortune Server",
-                    "Unable to start the server: %s." % self.server.errorString())
+                    f"Unable to start the server: {reason}.")
             self.close()
             return
 
@@ -123,9 +124,10 @@ class Dialog(QDialog):
             ipAddress = QHostAddress(QHostAddress.LocalHost)
 
         ipAddress = ipAddress.toString()
+        port = self.server.serverPort()
 
-        statusLabel.setText("The server is running on\n\nIP: %s\nport: %d\n\n"
-                "Run the Fortune Client example now." % (ipAddress, self.server.serverPort()))
+        statusLabel.setText(f"The server is running on\n\nIP: {ipAddress}\nport: {port}\n\n"
+                "Run the Fortune Client example now.")
 
         quitButton.clicked.connect(self.close)
 
diff --git a/examples/widgets/dialogs/classwizard/classwizard.py b/examples/widgets/dialogs/classwizard/classwizard.py
index addc089c6..b8ad04514 100644
--- a/examples/widgets/dialogs/classwizard/classwizard.py
+++ b/examples/widgets/dialogs/classwizard/classwizard.py
@@ -122,8 +122,10 @@ class ClassWizard(QtWidgets.QWizard):
         headerFile = QtCore.QFile(outputDir + '/' + header)
 
         if not headerFile.open(QtCore.QFile.WriteOnly | QtCore.QFile.Text):
+            name = headerFile.fileName()
+            reason = headerFile.errorString()
             QtWidgets.QMessageBox.warning(None, "Class Wizard",
-                    "Cannot write file %s:\n%s" % (headerFile.fileName(), headerFile.errorString()))
+                    f"Cannot write file {name}:\n{reason}")
             return
 
         headerFile.write(QtCore.QByteArray(block.encode("utf-8")))
@@ -175,8 +177,10 @@ class ClassWizard(QtWidgets.QWizard):
         implementationFile = QtCore.QFile(outputDir + '/' + implementation)
 
         if not implementationFile.open(QtCore.QFile.WriteOnly | QtCore.QFile.Text):
+            name = implementationFile.fileName()
+            reason = implementationFile.errorString()
             QtWidgets.QMessageBox.warning(None, "Class Wizard",
-                    "Cannot write file %s:\n%s" % (implementationFile.fileName(), implementationFile.errorString()))
+                    f"Cannot write file {name}:\n{reason}")
             return
 
         implementationFile.write(QtCore.QByteArray(block.encode("utf-8")))
@@ -389,7 +393,7 @@ class ConclusionPage(QtWidgets.QWizardPage):
     def initializePage(self):
         finishText = self.wizard().buttonText(QtWidgets.QWizard.FinishButton)
         finishText.replace('&', '')
-        self.label.setText("Click %s to generate the class skeleton." % finishText)
+        self.label.setText(f"Click {finishText} to generate the class skeleton.")
 
 
 if __name__ == '__main__':
diff --git a/examples/widgets/dialogs/findfiles/findfiles.py b/examples/widgets/dialogs/findfiles/findfiles.py
index 5e26f73ad..50432e7ed 100644
--- a/examples/widgets/dialogs/findfiles/findfiles.py
+++ b/examples/widgets/dialogs/findfiles/findfiles.py
@@ -130,7 +130,8 @@ class Window(QtWidgets.QDialog):
 
         for i in range(len(files)):
             progressDialog.setValue(i)
-            progressDialog.setLabelText("Searching file number %d of %d..." % (i, len(files)))
+            n = len(files)
+            progressDialog.setLabelText(f"Searching file number {i} of {n}...")
             QtCore.QCoreApplication.processEvents()
 
             if progressDialog.wasCanceled():
@@ -159,7 +160,8 @@ class Window(QtWidgets.QDialog):
 
             fileNameItem = QtWidgets.QTableWidgetItem(fn)
             fileNameItem.setFlags(fileNameItem.flags() ^ QtCore.Qt.ItemIsEditable)
-            sizeItem = QtWidgets.QTableWidgetItem("%d KB" % (int((size + 1023) / 1024)))
+            size_kb = int((size + 1023) / 1024)
+            sizeItem = QtWidgets.QTableWidgetItem(f"{size_kb} KB")
             sizeItem.setTextAlignment(QtCore.Qt.AlignVCenter | QtCore.Qt.AlignRight)
             sizeItem.setFlags(sizeItem.flags() ^ QtCore.Qt.ItemIsEditable)
 
@@ -168,7 +170,8 @@ class Window(QtWidgets.QDialog):
             self.filesTable.setItem(row, 0, fileNameItem)
             self.filesTable.setItem(row, 1, sizeItem)
 
-        self.filesFoundLabel.setText("%d file(s) found (Double click on a file to open it)" % len(files))
+        n = len(files)
+        self.filesFoundLabel.setText(f"{n} file(s) found (Double click on a file to open it)")
 
     def createButton(self, text, member):
         button = QtWidgets.QPushButton(text)
diff --git a/examples/widgets/dialogs/standarddialogs/standarddialogs.py b/examples/widgets/dialogs/standarddialogs/standarddialogs.py
index 5e0f80c4d..493f2bb54 100644
--- a/examples/widgets/dialogs/standarddialogs/standarddialogs.py
+++ b/examples/widgets/dialogs/standarddialogs/standarddialogs.py
@@ -185,7 +185,7 @@ class Dialog(QtWidgets.QDialog):
         i, ok = QtWidgets.QInputDialog.getInt(self,
                 "QInputDialog.getInteger()", "Percentage:", 25, 0, 100, 1)
         if ok:
-            self.integerLabel.setText("%d%%" % i)
+            self.integerLabel.setText(f"{i}%")
 
     def setDouble(self):
         d, ok = QtWidgets.QInputDialog.getDouble(self, "QInputDialog.getDouble()",
@@ -249,7 +249,8 @@ class Dialog(QtWidgets.QDialog):
                 "All Files (*);;Text Files (*.txt)", "", options)
         if files:
             self.openFilesPath = files[0]
-            self.openFileNamesLabel.setText("[%s]" % ', '.join(files))
+            file_list = ', '.join(files)
+            self.openFileNamesLabel.setText(f"[{file_list}]")
 
     def setSaveFileName(self):
         options = QtWidgets.QFileDialog.Options()
diff --git a/examples/widgets/draganddrop/draggabletext/draggabletext.py b/examples/widgets/draganddrop/draggabletext/draggabletext.py
index a9ef72c41..16e02cb90 100644
--- a/examples/widgets/draganddrop/draggabletext/draggabletext.py
+++ b/examples/widgets/draganddrop/draggabletext/draggabletext.py
@@ -62,8 +62,9 @@ class DragLabel(QLabel):
 
         mimeData = QMimeData()
         mimeData.setText(self.text())
-        mimeData.setData('application/x-hotspot',
-                b'%d %d' % (hotSpot.x(), hotSpot.y()))
+        hx = hotSpot.x()
+        hy = hotSpot.y()
+        mimeData.setData('application/x-hotspot', f'{hx} {hy}'.encode('utf-8'))
 
         pixmap = QPixmap(self.size())
         self.render(pixmap)
diff --git a/examples/widgets/graphicsview/dragdroprobot/dragdroprobot.py b/examples/widgets/graphicsview/dragdroprobot/dragdroprobot.py
index a72c9351b..95134c313 100644
--- a/examples/widgets/graphicsview/dragdroprobot/dragdroprobot.py
+++ b/examples/widgets/graphicsview/dragdroprobot/dragdroprobot.py
@@ -57,10 +57,9 @@ class ColorItem(QtWidgets.QGraphicsItem):
 
         self.color = QtGui.QColor(random(256), random(256), random(256))
 
+        (r, g, b) = (self.color.red(), self.color.green(), self.color.blue())
         self.setToolTip(
-            "QColor(%d, %d, %d)\nClick and drag this color onto the robot!" %
-              (self.color.red(), self.color.green(), self.color.blue())
-        )
+            f"QColor({r}, {g}, {b})\nClick and drag this color onto the robot!")
         self.setCursor(QtCore.Qt.OpenHandCursor)
 
     def boundingRect(self):
diff --git a/examples/widgets/itemviews/addressbook/addresswidget.py b/examples/widgets/itemviews/addressbook/addresswidget.py
index b3cc6591d..dfb0e42e5 100644
--- a/examples/widgets/itemviews/addressbook/addresswidget.py
+++ b/examples/widgets/itemviews/addressbook/addresswidget.py
@@ -94,7 +94,7 @@ class AddressWidget(QTabWidget):
         try:
             addresses.remove(address)
             QMessageBox.information(self, "Duplicate Name",
-                                    "The name \"%s\" already exists." % name)
+                                    f'The name "{name}" already exists.')
         except ValueError:
             # The address didn't already exist, so let's add it to the model.
 
@@ -129,13 +129,14 @@ class AddressWidget(QTabWidget):
 
         # Get the name and address of the currently selected row.
         indexes = selectionModel.selectedRows()
+        if len(indexes) != 1:
+            return
 
-        for index in indexes:
-            row = proxyModel.mapToSource(index).row()
-            ix = self.tableModel.index(row, 0, QModelIndex())
-            name = self.tableModel.data(ix, Qt.DisplayRole)
-            ix = self.tableModel.index(row, 1, QModelIndex())
-            address = self.tableModel.data(ix, Qt.DisplayRole)
+        row = proxyModel.mapToSource(indexes[0]).row()
+        ix = self.tableModel.index(row, 0, QModelIndex())
+        name = self.tableModel.data(ix, Qt.DisplayRole)
+        ix = self.tableModel.index(row, 1, QModelIndex())
+        address = self.tableModel.data(ix, Qt.DisplayRole)
 
         # Open an addDialogWidget, and only allow the user to edit the address.
         addDialog = AddDialogWidget()
@@ -216,12 +217,12 @@ class AddressWidget(QTabWidget):
             f = open(filename, "rb")
             addresses = pickle.load(f)
         except IOError:
-            QMessageBox.information(self, "Unable to open file: %s" % filename)
+            QMessageBox.information(self, f"Unable to open file: {filename}")
         finally:
             f.close()
 
         if len(addresses) == 0:
-            QMessageBox.information(self, "No contacts in file: %s" % filename)
+            QMessageBox.information(self, f"No contacts in file: {filename}")
         else:
             for address in addresses:
                 self.addEntry(address["name"], address["address"])
@@ -233,7 +234,7 @@ class AddressWidget(QTabWidget):
             pickle.dump(self.tableModel.addresses, f)
 
         except IOError:
-            QMessageBox.information(self, "Unable to open file: %s" % filename)
+            QMessageBox.information(self, f"Unable to open file: {filename}")
         finally:
             f.close()
 
diff --git a/examples/widgets/itemviews/fetchmore/fetchmore.py b/examples/widgets/itemviews/fetchmore/fetchmore.py
index c91874004..281cc166b 100644
--- a/examples/widgets/itemviews/fetchmore/fetchmore.py
+++ b/examples/widgets/itemviews/fetchmore/fetchmore.py
@@ -132,7 +132,7 @@ class Window(QtWidgets.QWidget):
         self.setWindowTitle("Fetch More Example")
 
     def updateLog(self, number):
-        self.logViewer.append("%d items added." % number)
+        self.logViewer.append(f"{number} items added.")
 
 
 if __name__ == '__main__':
diff --git a/examples/widgets/layouts/basiclayouts/basiclayouts.py b/examples/widgets/layouts/basiclayouts/basiclayouts.py
index 25a9b7760..ea46ad1e9 100644
--- a/examples/widgets/layouts/basiclayouts/basiclayouts.py
+++ b/examples/widgets/layouts/basiclayouts/basiclayouts.py
@@ -91,7 +91,7 @@ class Dialog(QtWidgets.QDialog):
         layout = QtWidgets.QHBoxLayout()
 
         for i in range(Dialog.NumButtons):
-            button = QtWidgets.QPushButton("Button %d" % (i + 1))
+            button = QtWidgets.QPushButton(f"Button {i + 1}")
             layout.addWidget(button)
 
         self.horizontalGroupBox.setLayout(layout)
@@ -101,7 +101,7 @@ class Dialog(QtWidgets.QDialog):
         layout = QtWidgets.QGridLayout()
 
         for i in range(Dialog.NumGridRows):
-            label = QtWidgets.QLabel("Line %d:" % (i + 1))
+            label = QtWidgets.QLabel(f"Line {i + 1}:")
             lineEdit = QtWidgets.QLineEdit()
             layout.addWidget(label, i + 1, 0)
             layout.addWidget(lineEdit, i + 1, 1)
diff --git a/examples/widgets/mainwindows/application/application.py b/examples/widgets/mainwindows/application/application.py
index 4fddff5c1..93500efe1 100644
--- a/examples/widgets/mainwindows/application/application.py
+++ b/examples/widgets/mainwindows/application/application.py
@@ -216,8 +216,9 @@ class MainWindow(QtWidgets.QMainWindow):
     def loadFile(self, fileName):
         file = QtCore.QFile(fileName)
         if not file.open(QtCore.QFile.ReadOnly | QtCore.QFile.Text):
+            reason = file.errorString()
             QtWidgets.QMessageBox.warning(self, "Application",
-                    "Cannot read file %s:\n%s." % (fileName, file.errorString()))
+                    f"Cannot read file {fileName}:\n{reason}.")
             return
 
         inf = QtCore.QTextStream(file)
@@ -236,9 +237,11 @@ class MainWindow(QtWidgets.QMainWindow):
             outf = QtCore.QTextStream(file)
             outf << self.textEdit.toPlainText()
             if not file.commit():
-                error = "Cannot write file %s:\n%s." % (fileName, file.errorString())
+                reason = file.errorString()
+                error = f"Cannot write file {fileName}:\n{reason}."
         else:
-            error = "Cannot open file %s:\n%s." % (fileName, file.errorString())
+            reason = file.errorString()
+            error = f"Cannot open file {fileName}:\n{reason}."
         QtWidgets.QApplication.restoreOverrideCursor()
 
         if error:
@@ -259,7 +262,7 @@ class MainWindow(QtWidgets.QMainWindow):
         else:
             shownName = 'untitled.txt'
 
-        self.setWindowTitle("%s[*] - Application" % shownName)
+        self.setWindowTitle(f"{shownName}[*] - Application")
 
     def strippedName(self, fullFileName):
         return QtCore.QFileInfo(fullFileName).fileName()
diff --git a/examples/widgets/mainwindows/dockwidgets/dockwidgets.py b/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
index 910f0aa73..53428b82c 100644
--- a/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
+++ b/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
@@ -134,8 +134,9 @@ class MainWindow(QMainWindow):
 
         file = QFile(filename)
         if not file.open(QFile.WriteOnly | QFile.Text):
+            reason = file.errorString()
             QMessageBox.warning(self, "Dock Widgets",
-                    "Cannot write file %s:\n%s." % (filename, file.errorString()))
+                    "Cannot write file {filename}:\n{reason}.")
             return
 
         out = QTextStream(file)
@@ -143,7 +144,7 @@ class MainWindow(QMainWindow):
         out << self.textEdit.toHtml()
         QApplication.restoreOverrideCursor()
 
-        self.statusBar().showMessage("Saved '%s'" % filename, 2000)
+        self.statusBar().showMessage(f"Saved '{filename}'", 2000)
 
     def undo(self):
         document = self.textEdit.document()
diff --git a/examples/widgets/painting/basicdrawing/basicdrawing.py b/examples/widgets/painting/basicdrawing/basicdrawing.py
index 9134ae49e..07e90ae22 100644
--- a/examples/widgets/painting/basicdrawing/basicdrawing.py
+++ b/examples/widgets/painting/basicdrawing/basicdrawing.py
@@ -153,8 +153,9 @@ class RenderArea(QWidget):
                 elif self.shape == RenderArea.Path:
                     painter.drawPath(path)
                 elif self.shape == RenderArea.Text:
+                    qv = qVersion()
                     painter.drawText(rect, Qt.AlignCenter,
-                                     "PySide 2\nQt %s" % qVersion())
+                                     f"PySide 6\nQt {qv}")
                 elif self.shape == RenderArea.Pixmap:
                     painter.drawPixmap(10, 10, self.pixmap)
 
diff --git a/examples/widgets/richtext/orderform/orderform.py b/examples/widgets/richtext/orderform/orderform.py
index ed7b29d61..3135e82e6 100644
--- a/examples/widgets/richtext/orderform/orderform.py
+++ b/examples/widgets/richtext/orderform/orderform.py
@@ -109,8 +109,8 @@ class MainWindow(QtWidgets.QMainWindow):
         cursor.insertBlock()
 
         date = QtCore.QDate.currentDate()
-        cursor.insertText("Date: %s" % date.toString('d MMMM yyyy'),
-                textFormat)
+        date_str = date.toString('d MMMM yyyy')
+        cursor.insertText(f"Date: {date_str}", textFormat)
         cursor.insertBlock()
 
         bodyFrameFormat = QtGui.QTextFrameFormat()
diff --git a/examples/widgets/tutorials/addressbook/part2.py b/examples/widgets/tutorials/addressbook/part2.py
index 92254ce1c..68446d3d0 100644
--- a/examples/widgets/tutorials/addressbook/part2.py
+++ b/examples/widgets/tutorials/addressbook/part2.py
@@ -141,10 +141,10 @@ class AddressBook(QtWidgets.QWidget):
         if name not in self.contacts:
             self.contacts[name] = address
             QtWidgets.QMessageBox.information(self, "Add Successful",
-                    "\"%s\" has been added to your address book." % name)
+                    f'"{name}" has been added to your address book.')
         else:
             QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                    "Sorry, \"%s\" is already in your address book." % name)
+                    f'Sorry, "{name}" is already in your address book.')
             return
 
         if not self.contacts:
diff --git a/examples/widgets/tutorials/addressbook/part3.py b/examples/widgets/tutorials/addressbook/part3.py
index c04b8f2b9..cfb150d7f 100644
--- a/examples/widgets/tutorials/addressbook/part3.py
+++ b/examples/widgets/tutorials/addressbook/part3.py
@@ -154,10 +154,10 @@ class AddressBook(QtWidgets.QWidget):
         if name not in self.contacts:
             self.contacts[name] = address
             QtWidgets.QMessageBox.information(self, "Add Successful",
-                    "\"%s\" has been added to your address book." % name)
+                    f'"{name}" has been added to your address book.')
         else:
             QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                    "Sorry, \"%s\" is already in your address book." % name)
+                    f'Sorry, "{name}" is already in your address book.')
             return
 
         if not self.contacts:
diff --git a/examples/widgets/tutorials/addressbook/part4.py b/examples/widgets/tutorials/addressbook/part4.py
index eca0be852..dbca3c099 100644
--- a/examples/widgets/tutorials/addressbook/part4.py
+++ b/examples/widgets/tutorials/addressbook/part4.py
@@ -165,26 +165,26 @@ class AddressBook(QtWidgets.QWidget):
             if name not in self.contacts:
                 self.contacts[name] = address
                 QtWidgets.QMessageBox.information(self, "Add Successful",
-                        "\"%s\" has been added to your address book." % name)
+                        f'"{name}" has been added to your address book.')
             else:
                 QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                        "Sorry, \"%s\" is already in your address book." % name)
+                        f'Sorry, "{name}" is already in your address book.')
                 return
 
         elif self.currentMode == self.EditingMode:
             if self.oldName != name:
                 if name not in self.contacts:
                     QtWidgets.QMessageBox.information(self, "Edit Successful",
-                            "\"%s\" has been edited in your address book." % self.oldName)
+                            f'"{self.oldName}" has been edited in your address book.')
                     del self.contacts[self.oldName]
                     self.contacts[name] = address
                 else:
                     QtWidgets.QMessageBox.information(self, "Edit Unsuccessful",
-                            "Sorry, \"%s\" is already in your address book." % name)
+                            f'Sorry, "{name}" is already in your address book.')
                     return
             elif self.oldAddress != address:
                 QtWidgets.QMessageBox.information(self, "Edit Successful",
-                        "\"%s\" has been edited in your address book." % name)
+                        f'"{name}" has been edited in your address book.')
                 self.contacts[name] = address
 
         self.updateInterface(self.NavigationMode)
@@ -200,7 +200,7 @@ class AddressBook(QtWidgets.QWidget):
 
         if name in self.contacts:
             button = QtWidgets.QMessageBox.question(self, "Confirm Remove",
-                    "Are you sure you want to remove \"%s\"?" % name,
+                    f'Are you sure you want to remove "{name}"?',
                     QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
 
             if button == QtWidgets.QMessageBox.Yes:
@@ -208,7 +208,7 @@ class AddressBook(QtWidgets.QWidget):
                 del self.contacts[name]
 
                 QtWidgets.QMessageBox.information(self, "Remove Successful",
-                        "\"%s\" has been removed from your address book." % name)
+                        f'"{name}" has been removed from your address book.')
 
         self.updateInterface(self.NavigationMode)
 
diff --git a/examples/widgets/tutorials/addressbook/part5.py b/examples/widgets/tutorials/addressbook/part5.py
index 27eb50a82..a513889ec 100644
--- a/examples/widgets/tutorials/addressbook/part5.py
+++ b/examples/widgets/tutorials/addressbook/part5.py
@@ -171,26 +171,26 @@ class AddressBook(QtWidgets.QWidget):
             if name not in self.contacts:
                 self.contacts[name] = address
                 QtWidgets.QMessageBox.information(self, "Add Successful",
-                        "\"%s\" has been added to your address book." % name)
+                        f'"{name}" has been added to your address book.')
             else:
                 QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                        "Sorry, \"%s\" is already in your address book." % name)
+                        f'Sorry, "{name}" is already in your address book.')
                 return
 
         elif self.currentMode == self.EditingMode:
             if self.oldName != name:
                 if name not in self.contacts:
                     QtWidgets.QMessageBox.information(self, "Edit Successful",
-                            "\"%s\" has been edited in your address book." % self.oldName)
+                            f'"{self.oldName}" has been edited in your address book.')
                     del self.contacts[self.oldName]
                     self.contacts[name] = address
                 else:
                     QtWidgets.QMessageBox.information(self, "Edit Unsuccessful",
-                            "Sorry, \"%s\" is already in your address book." % name)
+                            f'Sorry, "{name}" is already in your address book.')
                     return
             elif self.oldAddress != address:
                 QtWidgets.QMessageBox.information(self, "Edit Successful",
-                        "\"%s\" has been edited in your address book." % name)
+                        f'"{name}" has been edited in your address book.')
                 self.contacts[name] = address
 
         self.updateInterface(self.NavigationMode)
@@ -206,7 +206,7 @@ class AddressBook(QtWidgets.QWidget):
 
         if name in self.contacts:
             button = QtWidgets.QMessageBox.question(self, "Confirm Remove",
-                    "Are you sure you want to remove \"%s\"?" % name,
+                    f'Are you sure you want to remove "{name}"?',
                     QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
 
             if button == QtWidgets.QMessageBox.Yes:
@@ -214,7 +214,7 @@ class AddressBook(QtWidgets.QWidget):
                 del self.contacts[name]
 
                 QtWidgets.QMessageBox.information(self, "Remove Successful",
-                        "\"%s\" has been removed from your address book." % name)
+                        f'"{name}" has been removed from your address book.')
 
         self.updateInterface(self.NavigationMode)
 
@@ -268,7 +268,7 @@ class AddressBook(QtWidgets.QWidget):
                 self.addressText.setText(self.contacts[contactName])
             else:
                 QtWidgets.QMessageBox.information(self, "Contact Not Found",
-                        "Sorry, \"%s\" is not in your address book." % contactName)
+                        f'Sorry, "{contactName}" is not in your address book.')
                 return
 
         self.updateInterface(self.NavigationMode)
diff --git a/examples/widgets/tutorials/addressbook/part6.py b/examples/widgets/tutorials/addressbook/part6.py
index 70103380c..370c1ba9c 100644
--- a/examples/widgets/tutorials/addressbook/part6.py
+++ b/examples/widgets/tutorials/addressbook/part6.py
@@ -183,26 +183,26 @@ class AddressBook(QtWidgets.QWidget):
             if name not in self.contacts:
                 self.contacts[name] = address
                 QtWidgets.QMessageBox.information(self, "Add Successful",
-                        "\"%s\" has been added to your address book." % name)
+                        f'"{name}" has been added to your address book.')
             else:
                 QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                        "Sorry, \"%s\" is already in your address book." % name)
+                        f'Sorry, "{name}" is already in your address book.')
                 return
 
         elif self.currentMode == self.EditingMode:
             if self.oldName != name:
                 if name not in self.contacts:
                     QtWidgets.QMessageBox.information(self, "Edit Successful",
-                            "\"%s\" has been edited in your address book." % self.oldName)
+                            f'"{self.oldName}" has been edited in your address book.')
                     del self.contacts[self.oldName]
                     self.contacts[name] = address
                 else:
                     QtWidgets.QMessageBox.information(self, "Edit Unsuccessful",
-                            "Sorry, \"%s\" is already in your address book." % name)
+                            f'Sorry, "{name}" is already in your address book.')
                     return
             elif self.oldAddress != address:
                 QtWidgets.QMessageBox.information(self, "Edit Successful",
-                        "\"%s\" has been edited in your address book." % name)
+                        f'"{name}" has been edited in your address book.')
                 self.contacts[name] = address
 
         self.updateInterface(self.NavigationMode)
@@ -218,7 +218,7 @@ class AddressBook(QtWidgets.QWidget):
 
         if name in self.contacts:
             button = QtWidgets.QMessageBox.question(self, "Confirm Remove",
-                    "Are you sure you want to remove \"%s\"?" % name,
+                    f'Are you sure you want to remove "{name}"?',
                     QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
 
             if button == QtWidgets.QMessageBox.Yes:
@@ -226,7 +226,7 @@ class AddressBook(QtWidgets.QWidget):
                 del self.contacts[name]
 
                 QtWidgets.QMessageBox.information(self, "Remove Successful",
-                        "\"%s\" has been removed from your address book." % name)
+                        f'"{name}" has been removed from your address book.')
 
         self.updateInterface(self.NavigationMode)
 
@@ -280,7 +280,7 @@ class AddressBook(QtWidgets.QWidget):
                 self.addressText.setText(self.contacts[contactName])
             else:
                 QtWidgets.QMessageBox.information(self, "Contact Not Found",
-                        "Sorry, \"%s\" is not in your address book." % contactName)
+                        f'Sorry, "{contactName}" is not in your address book.')
                 return
 
         self.updateInterface(self.NavigationMode)
@@ -340,7 +340,7 @@ class AddressBook(QtWidgets.QWidget):
             out_file = open(str(fileName), 'wb')
         except IOError:
             QtWidgets.QMessageBox.information(self, "Unable to open file",
-                    "There was an error opening \"%s\"" % fileName)
+                    f'There was an error opening "{fileName}"')
             return
 
         pickle.dump(self.contacts, out_file)
@@ -358,7 +358,7 @@ class AddressBook(QtWidgets.QWidget):
             in_file = open(str(fileName), 'rb')
         except IOError:
             QtWidgets.QMessageBox.information(self, "Unable to open file",
-                    "There was an error opening \"%s\"" % fileName)
+                    f'There was an error opening "{fileName}"')
             return
 
         self.contacts = pickle.load(in_file)
diff --git a/examples/widgets/tutorials/addressbook/part7.py b/examples/widgets/tutorials/addressbook/part7.py
index c6a272636..d2c70d41a 100644
--- a/examples/widgets/tutorials/addressbook/part7.py
+++ b/examples/widgets/tutorials/addressbook/part7.py
@@ -189,26 +189,26 @@ class AddressBook(QtWidgets.QWidget):
             if name not in self.contacts:
                 self.contacts[name] = address
                 QtWidgets.QMessageBox.information(self, "Add Successful",
-                        "\"%s\" has been added to your address book." % name)
+                        f'"{name}" has been added to your address book.')
             else:
                 QtWidgets.QMessageBox.information(self, "Add Unsuccessful",
-                        "Sorry, \"%s\" is already in your address book." % name)
+                        f'Sorry, "{name}" is already in your address book.')
                 return
 
         elif self.currentMode == self.EditingMode:
             if self.oldName != name:
                 if name not in self.contacts:
                     QtWidgets.QMessageBox.information(self, "Edit Successful",
-                            "\"%s\" has been edited in your address book." % self.oldName)
+                            f'"{self.oldName}" has been edited in your address book.')
                     del self.contacts[self.oldName]
                     self.contacts[name] = address
                 else:
                     QtWidgets.QMessageBox.information(self, "Edit Unsuccessful",
-                            "Sorry, \"%s\" is already in your address book." % name)
+                            f'Sorry, "{name}" is already in your address book.')
                     return
             elif self.oldAddress != address:
                 QtWidgets.QMessageBox.information(self, "Edit Successful",
-                        "\"%s\" has been edited in your address book." % name)
+                        f'"{name}" has been edited in your address book.')
                 self.contacts[name] = address
 
         self.updateInterface(self.NavigationMode)
@@ -224,7 +224,7 @@ class AddressBook(QtWidgets.QWidget):
 
         if name in self.contacts:
             button = QtWidgets.QMessageBox.question(self, "Confirm Remove",
-                    "Are you sure you want to remove \"%s\"?" % name,
+                    f'Are you sure you want to remove "{name}"?',
                     QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No)
 
             if button == QtWidgets.QMessageBox.Yes:
@@ -232,7 +232,7 @@ class AddressBook(QtWidgets.QWidget):
                 del self.contacts[name]
 
                 QtWidgets.QMessageBox.information(self, "Remove Successful",
-                        "\"%s\" has been removed from your address book." % name)
+                        f'"{name}" has been removed from your address book.')
 
         self.updateInterface(self.NavigationMode)
 
@@ -286,7 +286,7 @@ class AddressBook(QtWidgets.QWidget):
                 self.addressText.setText(self.contacts[contactName])
             else:
                 QtWidgets.QMessageBox.information(self, "Contact Not Found",
-                        "Sorry, \"%s\" is not in your address book." % contactName)
+                        f'Sorry, "{contactName}" is not in your address book.')
                 return
 
         self.updateInterface(self.NavigationMode)
@@ -349,7 +349,7 @@ class AddressBook(QtWidgets.QWidget):
             out_file = open(str(fileName), 'wb')
         except IOError:
             QtWidgets.QMessageBox.information(self, "Unable to open file",
-                    "There was an error opening \"%s\"" % fileName)
+                    f'There was an error opening "{fileName}"')
             return
 
         pickle.dump(self.contacts, out_file)
@@ -367,7 +367,7 @@ class AddressBook(QtWidgets.QWidget):
             in_file = open(str(fileName), 'rb')
         except IOError:
             QtWidgets.QMessageBox.information(self, "Unable to open file",
-                    "There was an error opening \"%s\"" % fileName)
+                    f'There was an error opening "{fileName}"')
             return
 
         self.contacts = pickle.load(in_file)
@@ -425,7 +425,7 @@ class AddressBook(QtWidgets.QWidget):
         out_s << 'END:VCARD' << '\n'
 
         QtWidgets.QMessageBox.information(self, "Export Successful",
-                "\"%s\" has been exported as a vCard." % name)
+                f'"{name}" has been exported as a vCard.')
 
 
 class FindDialog(QtWidgets.QDialog):
diff --git a/examples/widgets/tutorials/cannon/t10.py b/examples/widgets/tutorials/cannon/t10.py
index ca7e9d9b7..1cfed53aa 100644
--- a/examples/widgets/tutorials/cannon/t10.py
+++ b/examples/widgets/tutorials/cannon/t10.py
@@ -77,9 +77,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/widgets/tutorials/cannon/t11.py b/examples/widgets/tutorials/cannon/t11.py
index c3d2e1271..dfc206d51 100644
--- a/examples/widgets/tutorials/cannon/t11.py
+++ b/examples/widgets/tutorials/cannon/t11.py
@@ -78,9 +78,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/widgets/tutorials/cannon/t12.py b/examples/widgets/tutorials/cannon/t12.py
index 290ecc82e..b94a28688 100644
--- a/examples/widgets/tutorials/cannon/t12.py
+++ b/examples/widgets/tutorials/cannon/t12.py
@@ -95,9 +95,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/widgets/tutorials/cannon/t13.py b/examples/widgets/tutorials/cannon/t13.py
index b54945e25..467346c2c 100644
--- a/examples/widgets/tutorials/cannon/t13.py
+++ b/examples/widgets/tutorials/cannon/t13.py
@@ -96,9 +96,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/widgets/tutorials/cannon/t14.py b/examples/widgets/tutorials/cannon/t14.py
index 19fb95ac8..420eeaa08 100644
--- a/examples/widgets/tutorials/cannon/t14.py
+++ b/examples/widgets/tutorials/cannon/t14.py
@@ -96,9 +96,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/widgets/tutorials/cannon/t8.py b/examples/widgets/tutorials/cannon/t8.py
index 3761b4353..e2d013eca 100644
--- a/examples/widgets/tutorials/cannon/t8.py
+++ b/examples/widgets/tutorials/cannon/t8.py
@@ -77,9 +77,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange.setRange(%d, %d)\n"
+            QtCore.qWarning("LCDRange.setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
@@ -111,7 +111,7 @@ class CannonField(QtWidgets.QWidget):
 
     def paintEvent(self, event):
         painter = QtGui.QPainter(self)
-        painter.drawText(200, 200, "Angle = %d" % self.currentAngle)
+        painter.drawText(200, 200, f"Angle = {self.currentAngle}")
 
 
 class MyWidget(QtWidgets.QWidget):
diff --git a/examples/widgets/tutorials/cannon/t9.py b/examples/widgets/tutorials/cannon/t9.py
index ca949c1ac..6d743357d 100644
--- a/examples/widgets/tutorials/cannon/t9.py
+++ b/examples/widgets/tutorials/cannon/t9.py
@@ -77,9 +77,9 @@ class LCDRange(QtWidgets.QWidget):
 
     def setRange(self, minValue, maxValue):
         if minValue < 0 or maxValue > 99 or minValue > maxValue:
-            QtCore.qWarning("LCDRange::setRange(%d, %d)\n"
+            QtCore.qWarning(f"LCDRange::setRange({minValue}, {maxValue})\n"
                     "\tRange must be 0..99\n"
-                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
+                    "\tand minValue must not be greater than maxValue")
             return
 
         self.slider.setRange(minValue, maxValue)
diff --git a/examples/xml/dombookmarks/dombookmarks.py b/examples/xml/dombookmarks/dombookmarks.py
index 0a8d01ec4..91aaf78d4 100644
--- a/examples/xml/dombookmarks/dombookmarks.py
+++ b/examples/xml/dombookmarks/dombookmarks.py
@@ -70,8 +70,9 @@ class MainWindow(QtWidgets.QMainWindow):
 
         inFile = QtCore.QFile(fileName)
         if not inFile.open(QtCore.QFile.ReadOnly | QtCore.QFile.Text):
+            reason = inFile.errorString()
             QtWidgets.QMessageBox.warning(self, "DOM Bookmarks",
-                    "Cannot read file %s:\n%s." % (fileName, inFile.errorString()))
+                    f"Cannot read file {fileName}:\n{reason}.")
             return
 
         if self.xbelTree.read(inFile):
@@ -87,8 +88,9 @@ class MainWindow(QtWidgets.QMainWindow):
 
         outFile = QtCore.QFile(fileName)
         if not outFile.open(QtCore.QFile.WriteOnly | QtCore.QFile.Text):
+            reason = outFile.errorString()
             QtWidgets.QMessageBox.warning(self, "DOM Bookmarks",
-                    "Cannot write file %s:\n%s." % (fileName, outFile.errorString()))
+                    "Cannot write file {fileName}:\n{reason}.")
             return
 
         if self.xbelTree.write(outFile):
@@ -151,7 +153,7 @@ class XbelTree(QtWidgets.QTreeWidget):
         ok, errorStr, errorLine, errorColumn = self.domDocument.setContent(device, True)
         if not ok:
             QtWidgets.QMessageBox.information(self.window(), "DOM Bookmarks",
-                    "Parse error at line %d, column %d:\n%s" % (errorLine, errorColumn, errorStr))
+                    f"Parse error at line {errorLine}, column {errorColumn}:\n{errorStr}")
             return False
 
         root = self.domDocument.documentElement()
@@ -215,7 +217,7 @@ class XbelTree(QtWidgets.QTreeWidget):
         item.setText(0, title)
 
         folded = (element.attribute('folded') != 'no')
-        self.setItemExpanded(item, not folded)
+        item.setExpanded(not folded)
 
         child = element.firstChildElement()
         while not child.isNull():