python爬虫基础之request设置问题

代码：
# -*- coding:utf-8 -*-
import urllib
import urllib2

page = 1
url = 'http://www.qiushibaike.com/hot/page/' + str(page)
user_agent = 'Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:45.0) Gecko/20100101 Firefox/45.0'
headers = {'User-Agent': user_agent}
try:
    request = urllib2.Request(url, headers)
***************************问题所在
改成：
    request = urllib2.Request(url, headers=headers)
************************************
    response = urllib2.urlopen(request)
    print response.read()
except urllib2.URLError, e:
    if hasattr(e, 'code'):
        print e.code
    if hasattr(e, 'reason'):
        print e.reason

报错：
G:\python27\python.exe D:/编程/PY/test_new.py
Traceback (most recent call last):
  File "D:/���/PY/test_new.py", line 11, in <module>
    response = urllib2.urlopen(request)
  File "G:\python27\lib\urllib2.py", line 126, in urlopen
    return _opener.open(url, data, timeout)
  File "G:\python27\lib\urllib2.py", line 400, in open
    response = self._open(req, data)
  File "G:\python27\lib\urllib2.py", line 418, in _open
    '_open', req)
  File "G:\python27\lib\urllib2.py", line 378, in _call_chain
    result = func(*args)
  File "G:\python27\lib\urllib2.py", line 1207, in http_open
    return self.do_open(httplib.HTTPConnection, req)
  File "G:\python27\lib\urllib2.py", line 1174, in do_open
    h.request(req.get_method(), req.get_selector(), req.data, headers)
  File "G:\python27\lib\httplib.py", line 958, in request
    self._send_request(method, url, body, headers)
  File "G:\python27\lib\httplib.py", line 992, in _send_request
    self.endheaders(body)
  File "G:\python27\lib\httplib.py", line 954, in endheaders
    self._send_output(message_body)
  File "G:\python27\lib\httplib.py", line 818, in _send_output
    self.send(message_body)
  File "G:\python27\lib\httplib.py", line 790, in send
    self.sock.sendall(data)
  File "G:\python27\lib\socket.py", line 224, in meth
    return getattr(self._sock,name)(*args)
TypeError: must be string or buffer, not dict

Process finished with exit code 1