Python 2 v. 3 xpath

问题

This code returns one element under Python 2.7.9 and no elements under 3.4.3. Why? How do I fix it for Python 3?

import requests
from lxml import html

page = requests.get('http://www.bloomberg.com/markets/rates-bonds/government-bonds/us/').text
tree = html.fromstring(page)

line = tree.xpath('//table[@class="std_table_module dual_border_data_table clear"][2]')
print(line)

来源：https://stackoverflow.com/questions/28766281/python-2-v-3-xpath