How to use the tldextract.tldextract.extract function in tldextract

'password', 'imgur', 'flickr', 'search', 'subscription', 'itunes',
            'siteindex', 'events', 'stop', 'jobs', 'careers', 'newsletter',
            'subscribe', 'academy', 'shopping', 'purchase', 'site-map',
            'shop', 'donate', 'newsletter', 'product', 'advert', 'info',
            'tickets', 'coupons', 'forum', 'board', 'archive', 'browse',
            'howto', 'how to', 'faq', 'terms', 'charts', 'services',
            'contact', 'plus', 'admin', 'login', 'signup', 'register',
            'developer', 'proxy']

        _valid_categories = []

        # TODO Stop spamming urlparse and tldextract calls...

        for p_url in valid_categories:
            path = urls.get_path(p_url)
            subdomain = tldextract.extract(p_url).subdomain
            conjunction = path + ' ' + subdomain
            bad = False
            for badword in stopwords:
                if badword.lower() in conjunction.lower():
                    if self.config.verbose:
                        print(('elim category url %s for subdomain '
                               'contain stopword!' % p_url))
                    bad = True
                    break
            if not bad:
                _valid_categories.append(p_url)

        _valid_categories.append('/')  # add the root

        for i, p_url in enumerate(_valid_categories):
            if p_url.startswith('://'):

def __init__(self):
		"""Loads in Ed and Olivier's domainRules.json file, now converted to a big (7k+ entry) dict object"""
		#import domainRules.json
		from domain_rules import domain_rules
		from tldextract.tldextract import extract
		self.extract = extract
		from nltk.stem.porter import PorterStemmer as PorterStemmer
		self.domain_rules = domain_rules
		#create stemmer
		self.Stemmer = PorterStemmer()