PyQt - running a loop inside GUI

Question

I've got a Python code with some while loop inside, but I don't know how to make it work with my PyQt GUI - I can only run the Qt window or that loop (but then windows doesn't show). Is there any solution to this? I read about some QThreads or QTimers, but I don't have any idea how to use it.

Solution

There is a question that is very similar to yours, Background thread with QThread in PyQt. The answer has 3 unique methods to using a qthread.

This tutorial may be very beneficial, http://joplaete.wordpress.com/2010/07/21/threading-with-pyqt4/

Here is also a very good example:

import sys
import urllib2

from PyQt4 import QtCore, QtGui


class DownloadThread(QtCore.QThread):
    def __init__(self, url, list_widget):
        QtCore.QThread.__init__(self)
        self.url = url
        self.list_widget = list_widget

    def run(self):
        info = urllib2.urlopen(self.url).info()
        self.list_widget.addItem('%s\n%s' % (self.url, info))


class MainWindow(QtGui.QWidget):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.list_widget = QtGui.QListWidget()
        self.button = QtGui.QPushButton("Start")
        self.button.clicked.connect(self.start_download)
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.button)
        layout.addWidget(self.list_widget)
        self.setLayout(layout)

    def start_download(self):
        urls = ['http://google.com', 'http://twitter.com', 'http://yandex.ru',
                'https://stackoverflow.com/', 'http://www.youtube.com/']
        self.threads = []
        for url in urls:
            downloader = DownloadThread(url, self.list_widget)
            self.threads.append(downloader)
            downloader.start()

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    window = MainWindow()
    window.resize(640, 480)
    window.show()
    sys.exit(app.exec_())

From here Updating GUI elements in MultiThreaded PyQT

Comments

[Admin]

You should post your code and your loops.

[Larry_C]

for url in urls: downloader = DownloadThread(url, self.list_widget) self.threads.append(downloader) # Correct typo? downloader.run()