Phil.py

import re
import urllib.request
from difflib import SequenceMatcher


def get_content(name):
    link = "https://ru.wikipedia.org/wiki/" + urllib.request.quote(name)
    try:
        with urllib.request.urlopen(link) as page:
            content = page.read().decode('utf-8')
            return urllib.request.unquote(content)
    except urllib.request.HTTPError:
        return None


def extract_content(page):
    true_page = urllib.request.unquote(page)
    pattern = r'<div id="bodyContent"(.*)<div class="visualClear">'
    result = re.search(pattern, true_page, re.DOTALL)
    return result.start(), result.end() if result is not None else (0, 0)


def extract_links(page, begin, end):
    true_page = urllib.request.unquote(page)
    content = true_page[begin:end]
    pattern = r'[hrefHREF]{4}=[\'"]/wiki/([-\w]+?)[\'"]'
    links = re.findall(pattern, content)
    return list(set(links)) if links is not None else []


def find_chain(start, finish):
    current_page = start
    passed_pages = set()
    passed_pages.add(start)
    route = []
    try:
        while True:
            route.append(current_page)
            current_links = get_links(current_page)
            if finish in current_links:
                route.append(finish)
                return route
            else:
                current_links = get_deviation_table(current_links, finish)
                current_page = get_best_link(current_links, passed_pages)
                passed_pages.add(current_page)
    except Exception:
        return None


def get_links(name):
    content = get_content(name)
    start, end = extract_content(content)
    return extract_links(content, start, end)


def get_deviation_table(words, pattern):
    deviation_table = []
    for word in words:
        deviation_table.append((SequenceMatcher(None, word, pattern).ratio(), word))
    deviation_table.sort(reverse=True)
    return deviation_table


def get_best_link(useful_links, extra_links):
    for propability, link in useful_links:
        if link not in extra_links:
            return link


def main():
    pass


if __name__ == '__main__':
    main()