from scrapy.selector import Selector
from scrapy.http import HtmlResponse

response = HtmlResponse(url='https://en.wikipedia.org/wiki/Pan_American_Games')
datas = Selector(response=response).xpath('//div[@class="thumb tleft"]')

from urllib2 import urlopen
from lxml import html

response = urlopen('https://en.wikipedia.org/wiki/Pan_American_Games')
page = html.fromstring(response.read())
datas = page.xpath('//div[@class="thumb tleft"]')