Python-сообщество

from http import cookies, client
from urllib.parse import urlencode, urlsplit, urljoin
from lxml.html import document_fromstring


class SimpleBrowser(object):
    def __init__(self, headers=None, timeout=10):
        self._cookies = cookies.SimpleCookie()
        self._headers = headers if (headers is not None) \
                                else [('User-Agent', 'SimpleBrowser/0.1')]
        self._headers.append(('Connection', 'close'))
        self._host = None
        self._conn = None
        self._timeout = timeout

    def __ensure_connection(self, host, scheme):
        if self._host == host:
            return

        if self._conn is not None:
            self._conn.close()

        self._host = host

        if scheme == 'http':
            self._conn = client.HTTPConnection(host, timeout=self._timeout)
        elif scheme == 'https':
            self._conn = client.HTTPSConnection(host, timeout=self._timeout)
        else:
            raise ValueError('Unknown scheme: %s' % scheme)

    def __prepare_url(self, url):
        parsed = urlsplit(url, scheme='http')
        host = parsed.netloc if parsed.netloc else self._host
        self.__ensure_connection(host, parsed.scheme)
        return '%s?%s' % (parsed.path, parsed.query)

    def close(self):
        if self._conn is not None:
            self._conn.close()
            self._conn = None
        self._host = None

    def add_header(self, name, value):
        self._headers.append((name, value))

    def add_cookie(self, name, value):
        self._cookies[name] = value

    def request(self, req, url, data=None):
        if isinstance(data, dict):
            data = urlencode(data)

        loc = self.__prepare_url(url)
        self._conn.putrequest(req, loc)
        for header in self._headers:
            self._conn.putheader(*header)
        cookies = self._cookies.output(attrs=[], header='')
        if cookies:
            self._conn.putheader('Cookie', cookies.strip())
        self._conn.endheaders(data)

        resp = self._conn.getresponse()
        resp_headers = dict(resp.getheaders())
        resp_body = resp.read()
        self._conn.close()
        if 'Set-Cookie' in resp_headers:
            self._cookies.load(resp_headers['Set-Cookie'])
        if 'Set-Cookie2' in resp_headers:
            self._cookies.load(resp_headers['Set-Cookie2'])

        if resp.status == client.OK:
            return (client.OK, document_fromstring(resp_body))
        elif resp.status in (client.MOVED_PERMANENTLY, client.FOUND):
            return self.request(req, resp_headers['Location'], data)
        else:
            return (resp.status, resp.reason)

    def get(self, url):
        return self.request('GET', url)

    def post(self, url, data):
        return self.request('POST', url, data)


if __name__ == '__main__':
    sb = SimpleBrowser()
    res, doc = sb.get('http://pogoda.yandex.ru/moscow/')
    if res == client.OK:
        for div in doc.cssselect("div.b-forecast__tday"):
            print(div.text)

try:
    from lxml import etree
    import urllib.request as rqc
except ImportError:
    print("import faled")
url = "http://www.plm-forum.ru/forum/viewforum.php?f=133"
f = rqc.urlopen(url)
data = f.read()
lt = etree.parse(data)
print("EOL")

&bull

import lxml.html
...
lt = lxml.html.fromstring(data)

lt = lxml.html.parse("http://www.plm-forum.ru/forum/viewforum.php?f=133")