Qt で QWebPage を使用して複数の URL を効率的に取得するにはどうすればよいですか?

<code class="python">from PyQt5.QtCore import pyqtSignal, QUrl
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWebEngineWidgets import QWebEnginePage

class WebPage(QWebEnginePage):
    htmlReady = pyqtSignal(str, str)

    def __init__(self, verbose=False):
        super().__init__()
        self._verbose = verbose
        self.loadFinished.connect(self.handleLoadFinished)

    def process(self, urls):
        self._urls = iter(urls)
        self.fetchNext()

    def fetchNext(self):
        try:
            url = next(self._urls)
        except StopIteration:
            return False
        else:
            self.load(QUrl(url))
        return True

    def processCurrentPage(self, html):
        self.htmlReady.emit(html, self.url().toString())
        if not self self.fetchNext():
            QApplication.instance().quit()

    def handleLoadFinished(self):
        self.toHtml(self.processCurrentPage)

    def javaScriptConsoleMessage(self, *args, **kwargs):
        if self._verbose:
            super().javaScriptConsoleMessage(*args, **kwargs)</code>

<code class="python">from PyQt4.QtCore import pyqtSignal, QUrl
from PyQt4.QtGui import QApplication
from PyQt4.QtWebKit import QWebPage

class WebPage(QWebPage):
    htmlReady = pyqtSignal(str, str)

    def __init__(self, verbose=False):
        super(WebPage, self).__init__()
        self._verbose = verbose
        self.mainFrame().loadFinished.connect(self.handleLoadFinished)

    def process(self, urls):
        self._urls = iter(urls)
        self.fetchNext()

    def fetchNext(self):
        try: 
            url = next(self._urls)
        except StopIteration:
            return False
        else:
            self.mainFram().load(QUrl(url))
        return True

    def processCurrentPage(self):
        self.htmlReady.emit(self.mainFrame().toHtml(), self.mainFrame().url().toString())
        if not self.fetchNext():
            QApplication.instance().quit()

    def javaScripConsoleMessage(self ,* args, **kwargs):
        if self._verbose:
            super(WebPage, self).javaScriptConsoleMessage(*args, **kwargs)</code>

<code class="python">from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication

# PyQt5
url_list = ['https://example.com', 'https://example2.com']
app = QApplication(sys.argv)
webpage = WebPage(verbose=True)
webpage.htmlReady.connect(my_html_processor)
webpage.process(url_list)
sys.exit(app.exec_())

# PyQt4
from PyQt4.QtCore import QUrl
from PyQt4.QtGui import QApplication
url_list = ['https://example.com', 'https://example2.com']
app = QApplication(sys.argv)
webpage = WebPage(verbose=True)
webpage.htmlReady.connect(my_html_processor)
webpage.process(url_list)
sys.exit(app.exec_())</code>