Mastering GUI Programming with Python

Simple downloading

To demonstrate the basic use of QNetworkAccessManager, we're going to build a simple command-line HTTP download tool. Open a blank file called downloader.py and let's start with some imports:

import sysfrom os import pathfrom PyQt5 import QtNetwork as qtnfrom PyQt5 import QtCore as qtc

Since we aren't doing a GUI here, we don't need QtWidgets or QtGui, just QtNetwork, and QtCore. We'll also use the standard library path module for some filesystem-based operations.

Let's create a QObject subclass for our download engine:

class Downloader(qtc.QObject):    def __init__(self, url):        super().__init__()        self.manager = qtn.QNetworkAccessManager(            finished=self.on_finished)        self.request = qtn.QNetworkRequest(qtc.QUrl(url)) self.manager.get(self.request) ...