HTTPError：在urllib2和BeautifulSoup中找不到？

Question

from lxml import html
import requests

# Initial attempt to scrape HTML from link using BeautifulSoup

obama_4427 = requests.get('http://millercenter.org/president/obama/speech-4427')
obama_4427_tree = html.fromstring(obama_4427.text)

# The speech text itself is stored in the HTML with an Xpath 
# of '//*[@id="transcript"]/p' and is a <div>

obama_4427_text = obama_4427_tree.xpath('//div[@id="transcript"]/p')
print(obama_4427_text)

import urllib2,sys
from bs4 import BeautifulSoup,NavigableString

obama_4427_url = 'http://millercenter.org/president/obama/speech-4427'
obama_4427_html = urllib2.urlopen(obama_4427_url).read()

# Second attempt, using User-Agent

import httplib
httplib.HTTPConnection.debuglevel = 1

import urllib2
request = urllib2.Request(obama_4427_url)
opener = urllib2.build_opener()
feeddata = opener.open(request).read()

我最终收到以下错误代码：

HTTPError：找不到

在第二次尝试中，我试图将自己标识为用户代理以获取能够抓取此演讲的权限，但未成功。我在这里缺少什么？

顺便说一句，我在Anaconda Spyder中运行Python 2.7。