Simple PyQt example with QThread and QProgressBar

qprogressbar_thread.py

from PyQt4 import QtCore, QtGui
import sys, time
 
class mythread(QtCore.QThread):
    
    total = QtCore.pyqtSignal(object)
    update = QtCore.pyqtSignal()
    
    def __init__(self, parent, n):
        super(mythread, self).__init__(parent)
        self.n = n
 
    def run(self):
        self.total.emit(self.n)
        i = 0
        while (i<self.n):
            if (time.time() % 1==0):
                i+=1
                #print str(i)
                self.update.emit()
 
# create the dialog for zoom to point
class progress(QtGui.QProgressBar):
    
    def __init__(self, parent=None): 
        super(progress, self).__init__(parent)
        # Set up the user interface from Designer. 
        self.setValue(0)
        
        self.thread = mythread(self, 3)

        self.thread.total.connect(self.setMaximum)
        self.thread.update.connect(self.update)
        self.thread.finished.connect(self.close)
        
        self.n = 0
        self.thread.start()
        
    def update(self):
        self.n += 1
        print self.n
        self.setValue(self.n)
 
if __name__=="__main__":
    app = QtGui.QApplication([])
    progressWidget = progress()
    progressWidget.move(300, 300)
    progressWidget.show()
    sys.exit(app.exec_())

Nice. For a more recent example based on PyQt5 see here! It's a multithreaded chat client:

mhermann's link isn't really all that directly applicable, since it doesn't just use PyQt5, it also uses his threading module. And the Python threading module. AND QThread. (That's in there, if you look deep enough.)

Cool and all, but if anyone's looking for simple examples of how to use QThread in PyQt5, this stackoverflow question has several good ones among its answers.

The way you've phrased this @ferdnyc implies something that isn't factually true. You make it sound like my examples require knowledge of some proprietary "threading module" of mine. That's not true. My link gives an examples that uses Python's threading module, without any dependence on special code of mine. Then, yes, it does give a further example that shows a more abstract (and imho useful) utility function. But it is a separate example that's again (imho useful), but not required for understanding the examples before that.

@mhermann Perhaps. But the title of the original gist is "Simple PyQt example with QThread and QProgressBar".

Thank you for sharing... I was searching for a couple of days about how can I update the QThread value from the main window like the QWindow application. Your sample code helps me alot.

Unluckily, there is no good documentation for QThread applications , shared memory etc side