import bs4
import requests


class Parser:
    _BAD_PREFIX_SET = {'Википедия:', 'Портал:'}

    def link_checker(self, link):
        for prefix in self._BAD_PREFIX_SET:
            if link['title'][:len(prefix)] == prefix:
                return False
        return True

    def all_links(self, html):
        soup = bs4.BeautifulSoup(html, features="html.parser")
        css_selector = 'div.mw-parser-output a[href^=\/wiki]:not([class])'
        links = soup.select(css_selector)
        return list(filter(lambda x: self.link_checker(x), links))g



class WebGraph:
    def __init__(self, start_link, target):
        self.start_link = start_link
        self.target = target
        self.parser = Parser()
        self.used = set()

    def is_neighbours(self):
        links = self.parser.all_links(requests.get(self.start_link).text)
        return self.target in [link['title'] for link in links]


graph = WebGraph('https://ru.wikipedia.org/wiki/Соединённые_Штаты_Америки', 'Великобритания')
print(graph.is_neighbours())