我已经做伪装了 为什么还是禁止我访问？ 谢谢大哥们

import requests
from bs4 import BeautifulSoup
import urllib.request
url = 'http://jandan.net/pic/page-2200'
header = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36',
'Cookie':'jdna=596e6fb28c1bb47f949e65e1ae03f7f5#1478086150813; Hm_lvt_fd93b7fb546adcfbcf80c4fc2b54da2c=1477990183,1478071048,1478086070; Hm_lpvt_fd93b7fb546adcfbcf80c4fc2b54da2c=1478086151; _ga=GA1.2.1283086952.1477990183',
'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
'Accept-Encoding':'gzip, deflate, sdch',
'Host':'jandan.net',
'Referer':'http://jandan.net/pic' }
source_code = requests.get(url,headers = header)
plain_text = source_code.text
Soup = BeautifulSoup(plain_text)
download_link = []
folder_path = 'C:\ASDF'
for pic_tag in Soup.find_all('img'):
pic_link = pic_tag.get('src')
download_link.append(pic_link)
print(download_link)
for item in download_link:
urllib.request.urlretrieve(item,folder_path + item[-8:])
print('done')
错误：：
Traceback (most recent call last):
File "D:/Daimafiles/c'c'c'c.py", line 24, in <module>
urllib.request.urlretrieve(item,folder_path + item[-8:])
File "D:\python\lib\urllib\request.py", line 187, in urlretrieve
with contextlib.closing(urlopen(url, data)) as fp:
File "D:\python\lib\urllib\request.py", line 162, in urlopen
return opener.open(url, data, timeout)
File "D:\python\lib\urllib\request.py", line 471, in open
response = meth(req, response)
File "D:\python\lib\urllib\request.py", line 581, in http_response
'http', request, response, code, msg, hdrs)
File "D:\python\lib\urllib\request.py", line 509, in error
return self._call_chain(*args)
File "D:\python\lib\urllib\request.py", line 443, in _call_chain
result = func(*args)
File "D:\python\lib\urllib\request.py", line 589, in http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden