PySide/PyQT non-blocking thread example

pyqt threading example.py

from PySide import QtCore, QtGui
import sys
import time

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        #Build a UI
        self.myLayout = QtGui.QVBoxLayout()
        self.myCentralWidget = QtGui.QWidget()
        self.myCentralWidget.setLayout(self.myLayout)
        self.setCentralWidget(self.myCentralWidget)

        self.progressBar = QtGui.QProgressBar()
        self.progressBar.setRange(0, 100)
        self.myLayout.addWidget(self.progressBar)

        self.startButton = QtGui.QPushButton("Start!")
        self.startButton.clicked.connect(self.start_thread)
        self.myLayout.addWidget(self.startButton)

        #Initialize the thread
        self.myThread = MyQThread()

    def start_thread(self):
        if not self.myThread.isRunning():
            self.myThread.maxRange = 1000
            self.myThread.completionMessage = "this is a completion message"
            self.myThread.completeSignal.connect(self.handle_thread_completion)
            self.myThread.progressSignal.connect(self.handle_progress_bar)
            self.myThread.start()

    @QtCore.Slot(int)
    def handle_progress_bar(self, e):
        self.progressBar.setValue(e)

    @QtCore.Slot(str)
    def handle_thread_completion(self, e):
        self.progressBar.setValue(0)
        QtGui.QMessageBox.information(self, "Done", e)

class MyQThread(QtCore.QThread):
    # Signals to relay thread progress to the main GUI thread
    progressSignal = QtCore.Signal(int)
    completeSignal = QtCore.Signal(str)

    def __init__(self, parent=None):
        super(MyQThread, self).__init__(parent)
        # You can change variables defined here after initialization - but before calling start()
        self.maxRange = 100
        self.completionMessage = "done."

    def run(self):
        # blocking code goes here
        emitStep = int(self.maxRange/100.0) # how many iterations correspond to 1% on the progress bar

        for i in range(self.maxRange):
            time.sleep(0.01)

            if i%emitStep==0:
                self.progressSignal.emit(i/emitStep)

        self.completeSignal.emit(self.completionMessage)

if __name__=="__main__":
    app = QtGui.QApplication(sys.argv)
    win = MainWindow()
    win.show()
    sys.exit(app.exec_())

Really? and what if you are calling a very long task that is calling hundreds of several small tasks or functions??
How will you do that ?

Imagine you have a controller that is calling a function (very long task) which it calls also too many functions of other classes in order to complete the task. How then you will do that into the run function? You can add that long Task function into the loop!!

All the examples are only talking about updating the progress bar counter and completion percentage.
There is so many cases that are more than that.