import lxml.html
with open('posts.txt', 'a', encoding='utf-8') as f:
    for p in range(43):
        page = lxml.html.parse(r'http://ostanovinasilie.org/category/news/page/%d/' % p)
        for i in page.xpath('.//div[starts-with(@id, "post")]//a'):
            post = lxml.html.parse(i.attrib['href']).xpath('.//div[starts-with(@id, "post")]')
            f.write(post[0].text_content())

import lxml.html
with open('posts.html', 'a', encoding='utf-8') as f:
    for p in range(42, 0, -1):
        page = lxml.html.parse(r'http://ostanovinasilie.org/category/news/page/%d/' % p)
        for i in page.xpath('.//div[starts-with(@id, "post")]//a'):
            post = lxml.html.parse(i.attrib['href']).xpath('.//div[starts-with(@id, "post")]')
            f.write(lxml.html.tostring(post[0], method='html').decode('utf-8'))