Memory leak PyQT5

test.py

from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWebKitWidgets import QWebView
from PyQt5.QtWebKit import QWebSettings

class Crawler(QWebView):
    def __init__(self):
        QWebView.__init__(self)

        self.settings().setMaximumPagesInCache(0)
        self.settings().setObjectCacheCapacities(0, 0, 0)
        self.settings().setOfflineStorageDefaultQuota(0)
        self.settings().setOfflineWebApplicationCacheQuota(0)
        #self.settings().setAttribute(QWebSettings.AutoLoadImages, False)

        self.loadFinished.connect(self._result_available)

    def start(self):
        self.load(QUrl('http://google.com'))
        self.load(QUrl('http://facebook.com'))
        self.load(QUrl('http://youtube.com'))
        self.load(QUrl('http://yahoo.com'))
        self.load(QUrl('http://amazon.com'))
        self.load(QUrl('http://bing.com'))
        self.load(QUrl('http://ebay.com'))
        self.load(QUrl('http://wikipedia.org'))
        self.load(QUrl('http://craigslist.org'))
        self.load(QUrl('http://linkedin.com'))
        self.load(QUrl('http://live.com'))
        self.load(QUrl('http://twitter.com'))
        self.load(QUrl('http://blogspot.com'))
        self.load(QUrl('http://aol.com'))
        self.load(QUrl('http://go.com'))
        self.load(QUrl('http://pinterest.com'))
        self.load(QUrl('http://msn.com'))
        self.load(QUrl('http://tumblr.com'))
        self.load(QUrl('http://cnn.com'))
        self.load(QUrl('http://ask.com'))
        self.load(QUrl('http://huffingtonpost.com'))
        self.load(QUrl('http://netflix.com'))
        self.load(QUrl('http://paypal.com'))
        self.load(QUrl('http://weather.com'))
        self.load(QUrl('http://conduit.com'))
        self.load(QUrl('http://espn.go.com'))
        self.load(QUrl('http://instagram.com'))
        self.load(QUrl('http://wordpress.com'))
        self.load(QUrl('http://bankofamerica.com'))
        self.load(QUrl('http://akamihd.net'))
        self.load(QUrl('http://imdb.com'))
        self.load(QUrl('http://chase.com'))
        self.load(QUrl('http://microsoft.com'))
        self.load(QUrl('http://about.com'))
        self.load(QUrl('http://avg.com'))
        self.load(QUrl('http://pornhub.com'))
        self.load(QUrl('http://comcast.net'))
        self.load(QUrl('http://foxnews.com'))
        self.load(QUrl('http://apple.com'))
        self.load(QUrl('http://walmart.com'))
        self.load(QUrl('http://xhamster.com'))
        self.load(QUrl('http://mywebsearch.com'))
        self.load(QUrl('http://wellsfargo.com'))
        self.load(QUrl('http://xvideos.com'))
        self.load(QUrl('http://yelp.com'))
        self.load(QUrl('http://imgur.com'))
        self.load(QUrl('http://nytimes.com'))
        self.load(QUrl('http://nbcnews.com'))
        self.load(QUrl('http://cnet.com'))
        self.load(QUrl('http://reddit.com'))
        self.load(QUrl('http://adobe.com'))
        self.load(QUrl('http://ehow.com'))
        self.load(QUrl('http://pandora.com'))
        self.load(QUrl('http://pch.com'))
        self.load(QUrl('http://hulu.com'))
        self.load(QUrl('http://zedo.com'))
        self.load(QUrl('http://etsy.com'))
        self.load(QUrl('http://flickr.com'))
        self.load(QUrl('http://outbrain.com'))
        self.load(QUrl('http://optmd.com'))
        self.load(QUrl('http://indeed.com'))
        self.load(QUrl('http://livejasmin.com'))
        self.load(QUrl('http://zillow.com'))
        self.load(QUrl('http://target.com'))
        self.load(QUrl('http://xnxx.com'))
        self.load(QUrl('http://homedepot.com'))
        self.load(QUrl('http://redtube.com'))
        self.load(QUrl('http://answers.com'))
        self.load(QUrl('http://thepiratebay.sx'))
        self.load(QUrl('http://att.com'))
        self.load(QUrl('http://shopathome.com'))
        self.load(QUrl('http://wikia.com'))
        self.load(QUrl('http://dailymail.co.uk'))
        self.load(QUrl('http://usps.com'))
        self.load(QUrl('http://babylon.com'))
        self.load(QUrl('http://ups.com'))
        self.load(QUrl('http://bestbuy.com'))
        self.load(QUrl('http://youporn.com'))
        self.load(QUrl('http://reference.com'))
        self.load(QUrl('http://godaddy.com'))
        self.load(QUrl('http://groupon.com'))
        self.load(QUrl('http://deviantart.com'))
        self.load(QUrl('http://usatoday.com'))
        self.load(QUrl('http://pof.com'))
        self.load(QUrl('http://capitalone.com'))
        self.load(QUrl('http://bbc.co.uk'))
        self.load(QUrl('http://washingtonpost.com'))
        self.load(QUrl('http://match.com'))
        self.load(QUrl('http://drudgereport.com'))
        self.load(QUrl('http://mlb.com'))
        self.load(QUrl('http://tripadvisor.com'))
        self.load(QUrl('http://pogo.com'))
        self.load(QUrl('http://verizonwireless.com'))
        self.load(QUrl('http://blogger.com'))
        self.load(QUrl('http://buzzfeed.com'))
        self.load(QUrl('http://doublepimp.com'))
        self.load(QUrl('http://inksr.com'))
        self.load(QUrl('http://delta-search.com'))
        self.load(QUrl('http://fedex.com'))
        self.load(QUrl('http://inksdata.com'))
        self.load(QUrl('http://oyodomo.com'))
        self.load(QUrl('http://aweber.com'))
        self.load(QUrl('http://abcnews.go.com'))
        self.load(QUrl('http://vimeo.com'))
        self.load(QUrl('http://hootsuite.com'))
        self.load(QUrl('http://bleacherreport.com'))
        self.load(QUrl('http://lowes.com'))
        self.load(QUrl('http://yellowpages.com'))
        self.load(QUrl('http://americanexpress.com'))
        self.load(QUrl('http://tube8.com'))
        self.load(QUrl('http://yieldmanager.com'))
        self.load(QUrl('http://salesforce.com"'))

    def _result_available(self, ok):
        print('got it!')

        self.settings().clearMemoryCaches() # it doesn't help
        self.settings().clearIconDatabase()

        self.start() # next try

if __name__ == '__main__':
    app = QApplication([])
    crawler = Crawler()
    crawler.start()
    app.exec_()