def checkRobots(self):
if self.domain[len(self.domain)-1] != "/":
self.domain += "/"
request = Request(self.domain+"robots.txt", headers={"User-Agent":config.crawler_user_agent})
self.rp = RobotFileParser()
self.rp.set_url(self.domain+"robots.txt")
self.rp.read()
def _get_request_delay(
host: str,
url: str,
robots_parser: RobotFileParser,
delay_mapping: Dict[str, Union[int, float]],
default_delay: Union[int, float],
) -> Union[int, float]:
pass
crawl_delay = robots_parser.crawl_delay('*')
if crawl_delay is not None:
delay_mapping[host] = crawl_delay
logger.debug(
'returning crawl delay value "%s" from robots.txt for url %s',
crawl_delay, url)
return crawl_delay
request_rate = robots_parser.request_rate('*')
if request_rate is not None:
request_delay = request_rate.seconds / request_rate.requests
delay_mapping[host] = request_delay
logger.debug(
'computing value "%s" from request delay info (%s/%s) from robots.txt for url %s',
request_delay,
request_rate.requests,
request_rate.seconds,
url,
)
return request_delay
delay_mapping[host] = default_delay
logger.debug('returning default delay value "%s" for url %s',
default_delay, url)
return default_delay
def is_allowed(self): if self.site.robots_status==200: parser = RobotFileParser() lines = io.StringIO(self.site.robots).readlines() parser.parse(lines) return parser.can_fetch(settings.USER_AGENT, self.get_url()) return True
def analyze_badbots(db, filename, max_entries=100000, max_bots=100):
useragents = defaultdict(int)
for i, entry in enumerate(db):
parser = RobotFileParser(entry.url)
parser.parse(entry.body.split("\n"))
bans = [e for e in parser.entries if len(e.rulelines) == 1 and
not e.rulelines[0].allowance and e.rulelines[0].path == '/']
for ban in bans:
for useragent in ban.useragents:
useragents[useragent] += 1
if i >= max_entries:
break
useragents = sorted(useragents.items(), key=lambda x: -x[1])
with open(filename, "w") as output:
output.write("useragent\tcount\ttype\tinfolink\tcompany\thomepage\n")
for useragent, count in useragents[:max_bots]:
agenttype, info, company, homepage = BOT_TYPES.get(useragent, ('', '', '', ''))
if not info:
info = DEFAULT_USERAGENT_URL % useragent
output.write("%s\t%s\t%s\t%s\t%s\t%s\n" % (useragent, count, agenttype, info,
company, homepage))
return useragents
def get_robot_file_parser(start_url: str,
**kwargs) -> Union[RobotFileParser, None]:
"""Returns :class:`~python:urllib.robotparser.RobotFileParser` object from given URL.
If no ``robots.txt`` file is found or error occurs, returns ``None``.
:param start_url: URL from which ``robots.txt`` will be collected.
:param kwargs: Will be passed to :func:`get_html`.
.. seealso:: :func:`async_get_robot_file_parser`
"""
try:
parsed_url = ParsedUrl(start_url)
robot_txt_url = f"{parsed_url.scheme}://{parsed_url.netloc}/robots.txt"
rp = RobotFileParser(robot_txt_url)
text = get_html(robot_txt_url,
check_http_content_type=False,
return_response_object=False,
raise_for_status=True,
**kwargs)
lines = [line.strip() for line in text.split("\n") if line != '']
rp.parse(lines)
return rp
except Exception as e: # Exceptions from URL parsing, HTML retrieval and robot file parsing
logging.warning(
f"Unable to retrieve robots.txt from {start_url}. Reason: {e}")
return None
def analyze_badbots(db, filename, max_entries=100000, max_bots=100):
useragents = defaultdict(int)
for i, entry in enumerate(db):
parser = RobotFileParser(entry.url)
parser.parse(entry.body.split("\n"))
bans = [
e for e in parser.entries if len(e.rulelines) == 1
and not e.rulelines[0].allowance and e.rulelines[0].path == '/'
]
for ban in bans:
for useragent in ban.useragents:
useragents[useragent] += 1
if i >= max_entries:
break
useragents = sorted(useragents.items(), key=lambda x: -x[1])
with open(filename, "w") as output:
output.write("useragent\tcount\ttype\tinfolink\tcompany\thomepage\n")
for useragent, count in useragents[:max_bots]:
agenttype, info, company, homepage = BOT_TYPES.get(
useragent, ('', '', '', ''))
if not info:
info = DEFAULT_USERAGENT_URL % useragent
output.write(
"%s\t%s\t%s\t%s\t%s\t%s\n" %
(useragent, count, agenttype, info, company, homepage))
return useragents
def get_robots(self):
rp = RobotFileParser()
if self.robots_content:
rp.parse(self.robots_content)
else:
rp.allow_all = True
return rp
def _init_robots(self, root_url):
url = urlparse(root_url)
robots_url = url.scheme + '://' + url.netloc + '/robots.txt'
parser = RobotFileParser(robots_url)
parser.read()
return parser
def __init__(self, location: str, get_accredited: bool):
self._robot_parser = RobotFileParser()
self._robot_parser.set_url(urljoin(ICFG.STARTING_URL, 'robots.txt'))
self._robot_parser.read()
self._site_maps = self._robot_parser.site_maps()
self.location = location.lower()
self._acc = get_accredited
def __init__(self, robotstxt_body, spider):
from urllib.robotparser import RobotFileParser
self.spider = spider
robotstxt_body = decode_robotstxt(robotstxt_body,
spider,
to_native_str_type=True)
self.rp = RobotFileParser()
self.rp.parse(robotstxt_body.splitlines())
def __init__(self, basicUrl, pageLimit, level):
self._basicUrl = basicUrl
self._robotParser = RobotFileParser()
self._urlRegex = re.compile(basicUrl)
self._pageCount = pageLimit #A limit of pages
self._pageHeap = PriorityQueue()
self._visited = set()
self._level = level
def __init__(self, base_url):
try:
url = urljoin(base_url, 'robots.txt')
self.rp = RobotFileParser()
self.set_url(url)
self.rp.read()
except:
self.rp = None
def http_open(self, request):
url = request.get_full_url()
host = urlsplit(url)[1]
robots_url = urlunsplit(('http', host, '/robots.txt', '', ''))
rp = RobotFileParser(robots_url)
rp.read()
if not rp.can_fetch(self.agentname, url):
raise RuntimeError('Forbidden by robots.txt')
return urllib2.HTTPHandler.http_open(self, request)
class Crawler(Thread):
def __init__(self, scheduler, id):
Thread.__init__(self)
self.scheduler = scheduler
self.robot_parser = RobotFileParser()
self.running = True
self.id = id
def run(self):
global RUNNING
print(self.id,"running!")
while RUNNING and self.running:
url = self.scheduler.next()
while url is None:
sleep(2)
url = self.scheduler.next()
try:
''' Check robots.txt '''
parsed_url = urlparse(url)
robots_url = parsed_url.scheme + "://" + parsed_url.netloc + "/robots.txt"
robots_response = urlopen(robots_url, timeout=2)
robots_file = robots_response.read()
self.robot_parser.parse(robots_file.decode('utf-8').splitlines())
if not self.robot_parser.can_fetch("*", url):
#print(self.id,"is not allowed to fetch",url)
continue
''' Fetch the url '''
print(self.id,"->",url)
response = urlopen(url, timeout=2)
data = response.read().decode('utf-8', errors='ignore')
data = data.split('href="')
del data[0]
data = sorted(data, key=len)
except (HTTPError,TimeoutError,ConnectionResetError,UnicodeDecodeError,BaseException):
data = []
except URLError as e:
print(url,"->",str(e))
data = []
for d in data:
d = d[:d.find('"')]
if d.endswith('/'):
d = d[:-1]
''' Format relative URLs '''
if not d.startswith("http://"):
path = parsed_url.path
url = path[:path.rfind("/")]
while d.startswith("../"):
url = url[:url.rfind("/")]
d = d[3:]
self.scheduler.add(parsed_url.scheme + \
"://" + parsed_url.netloc + \
url + "/" + d)
else:
self.scheduler.add(d)
def check_robot_txt(url):
try:
# proxy_handler = ProxyHandler(
# {
# 'http' : 'http://127.0.0.1:63231',
# 'https' : 'http://127.0.0.1:63231'
# }
# )
#
# opener = build_opener(proxy_handler)
rp = RobotFileParser(url + '/robots.txt')
rp.read()
# rp.parse(urlopen(url.read().decode('utf-8').split('\n')))
print(rp.can_fetch('*', url + '/stock/'))
# print("***************1")
# response = opener.open('https://www.baidu.com')
# print("***************2")
# print(response.read().decode('utf-8'))
# headers = {'User-Agent': 'Mozilla / 5.0(Macintosh;Intel Mac OS X) AppleWebKit / 537.36(KHTML, like Gecko)',
# 'Host': 'httpbin.org'}
# dict = {'name':'Tobi'}
#
# username= '******'
# password= '******'
#
# url = 'http://localhost:5000'
#
# p = urllib.request.HTTPPasswordMgrWithDefaultRealm()
# p.add_password(None,url,username,password)
# auth_handler = urllib.request.HTTPBasicAuthHandler(p)
# opener = urllib.request.build_opener(auth_handler)
#
# response = opener.open(url)
# html = response.read().decode('utf-8')
# print(html)
# request = urllib.request.Request('http://httpbin.org/post', headers=headers, data=bytes(urllib.parse.urlencode(dict),encoding='utf8'), method='POST')
# print("***************")
# response = urllib.request.urlopen(request, context=ssl._create_unverified_context())
# if response.status != 200:
# print('status : ' + response.status)
# print("*******result********")
# print(response.read().decode('utf-8'))
# print(type(response))
# print(response.status)
# print(response.getheaders())
# print(response.getheader('Server'))
except URLError as e:
# if isinstance(e.reason, socket.timeout):
# print('time out!!!')
print(e.reason)
return
class Driver:
def __init__(self,
root_url: str,
header: str,
access_delay: int = 3,
cookies: dict = None,
logger=None):
self.logger = logger
self.root_url = root_url
self.cookies = cookies
self.header = header
self.access_delay = access_delay
self.now_content = None
self.robots = None
self.load_robots_txt()
def load_robots_txt(self):
self.robots = RobotFileParser()
self.robots.set_url(self.root_url + '/robots.txt')
self.robots.read()
def get(self, path):
try:
sleep(self.access_delay)
url = f'{self.root_url}/{path}'
if self.robots.can_fetch("*", url):
res = requests.get(url,
headers=self.header,
cookies=self.cookies)
if self.logger is not None:
self.logger.debug(f"Access to {url}.")
self.now_content = BeautifulSoup(res.text, 'html.parser')
else:
if self.logger is not None:
self.logger.warning(
f"Access to this url is prohibited by robots.txt.\n<*>[URL={url}]"
)
except Exception as e:
if self.logger is not None:
self.logger.warning(e)
def find_element_by_class_name(self, name):
return self.now_content.select('.' + name)[0]
def find_elements_by_class_name(self, name):
return self.now_content.select('.' + name)
def find_element_by_id(self, name):
return self.now_content.select('#' + name)[0]
def find_elements_by_id(self, name):
return self.now_content.select('#' + name)
def find_element_by_tag(self, name):
return self.now_content.find_all(name)
def can_fetch(self, url):
parsed_url = urlparse(url)
# Fetching and parsing the robots.txt file can be expensive in it-self.
# Let's cache the RobotFileParser instances, one per host, on the
# scraper itself to reuse them for consecutive queries.
rfp = self.robot_file_parsers.get(parsed_url.hostname)
if rfp is None:
rfp = RobotFileParser(self.get_robot_url(url))
rfp.read()
self.robot_file_parsers[parsed_url.hostname] = rfp
return rfp.can_fetch(self.user_agent, parsed_url.path)
class CrawlController(object):
def __init__(self):
self._rp = RobotFileParser()
def allow(self, p_robots_uri, p_target_uri):
http = urllib3.PoolManager()
r = http.request('GET', p_robots_uri)
if r.data:
self._rp.parse(r.data.decode('utf-8').splitlines())
return rp.can_fetch('*', p_target_uri)
return True
def test_robots_txt(self):
parser = RobotFileParser(self.live_server_url + '/robots.txt')
parser.read()
url = self.live_server_url + '/index.html'
for robot in self.robots:
self.assertTrue(parser.can_fetch(robot, url))
url = self.live_server_url + '/admin/'
for robot in self.robots:
self.assertFalse(parser.can_fetch(robot, url))
def __getParser(self, url):
if url == '':
return False
site = 'https://' + url + '/robots.txt'
# print("robotparse: " + site)
try:
rp = RobotFileParser(site)
rp.read()
except Exception as e:
return False
else:
return rp
def check_robots(base_url, ext_url):
'''
Check the robots.txt
Prints note if base_url + ext_url is legal for crawling
'''
bot = RobotFileParser(base_url + '/robots.txt')
bot.read()
if bot.can_fetch('*', base_url + ext_url):
print('robots.txt permits parsing')
else:
print('Do not parse')
return bot
def request(self, url: str) -> None:
""" Perform robots.txt request """
if self.state is not None:
return
try:
self.state = RobotFileParser()
self.state.set_url(url)
self.state.read()
except Exception:
self.state = False
def __init__(self, scheme: str, hostname: str):
self.scheme = scheme
self.hostname = hostname
self.last_time = 0
self._urls = set()
self._queue = deque()
# parse robots.txt
self._robot_parser = RobotFileParser()
self._robot_parser.set_url("{}://{}/robots.txt".format(
scheme, hostname))
self._robot_parser.read()
def filter_googlebot(entries):
""" Given a bunch of robots.txt entries, figure out if googlebot is allowed
but other random bots are banned. yields tuples of (entry, reppy.Robots) objects
that match this condition"""
for entry in entries:
if entry.status_code != 200:
continue
parser = RobotFileParser(entry.url)
parser.parse(entry.body.split("\n"))
if parser.can_fetch("GoogleBot", "/") and not parser.can_fetch("BensCoolBot", "/"):
yield entry, parser
def _robot_parser(self, txt, url):
"""Parses robots.txt with user-agent="*".
:param txt: robots.txt to parse
:param url: URL to check
:returns: if url is allowed in robots.txt
:rtype: bool
"""
parser = RobotFileParser()
if txt:
parser.parse(txt.decode("ascii", "replace").splitlines())
return parser.can_fetch("*", url)
else:
return True
class Exclusion(object):
def __init__(self):
self.robot_cache = {}
self.rp = RobotFileParser()
# Broken? disallows anything in the robots.txt.
# Even if it is marked with Allow:
def test_url(self, url):
self.rp = RobotFileParser()
robot_url = uu.domain_name(url) + '/robots.txt'
self.rp.set_url(robot_url)
self.rp.read()
return self.rp.can_fetch('*', url)
def can_fetch(self, url):
parse = urllib.parse.urlparse(url)
hostname = parse.hostname
try:
robot = self.robot[hostname]
except Exception:
roboturl = urllib.parse.urlunparse((parse.scheme,parse.netloc,"robots.txt","","",""))
robot = RobotFileParser(roboturl)
try:
robot.read()
except Exception:
robot = _RobotAllowAll()
self.__robots[hostname] = robot
return robot.can_fetch("*", url)
async def parse_robots(session, base):
"""Fetches and parses the robots.txt file from a given base URL. Returns an instance of
RobotFileParser."""
url = urljoin(base, "robots.txt")
async with session.get(url) as response:
status = response.status
text = await response.text()
robot_parser = RobotFileParser()
if status == 200:
robot_parser.parse(text.splitlines())
else:
robot_parser.allow_all = True
return robot_parser
class RobotsTxt:
def __init__(self, base_url):
try:
url = urljoin(base_url, 'robots.txt')
self.rp = RobotFileParser()
self.set_url(url)
self.rp.read()
except:
self.rp = None
def canFetch(self, url):
if self.rp is None:
return True
else:
return self.rp.can_fetch('*', url)
def __init__(self, url: str, api_key: str = None, authorizer=None):
parsed_url = parse_url_from_string(url.rstrip("/"))
self.host = parsed_url.host
self.url = str(parsed_url)
self.api_key = api_key or ''
self._ignore_robots = False
self.robots = RobotFileParser(urljoin(self.url, 'robots.txt'))
self._authorizer = authorizer
# Lazily-evaluated objects
self._session = None
self._taxonomies = None
self._informationobjects = None
self._virtual_taxonomies = None
self._virtual_authorities = None
def add_robot(self, base_url):
resp = download(base_url, self.config, self.logger)
if resp.raw_response is not None:
robot_list = resp.raw_response.content.decode().split("\n")
# Adds the robots.txt in a global dictionary, returning the read robot.txt
if base_url not in self.robots:
robots_file = RobotFileParser()
if resp.raw_response is not None and resp.status != 404:
robots_file.parse(robot_list)
self.robots[base_url] = robots_file
return self.robots[base_url]
class RobotsTxt:
def __init__(self) -> None:
self.state = None # type: Any
def allowed(self, url: URL) -> bool:
# We don't have info about this domain for now, so we going to request
# robots.txt
if self.state is None:
self.request(url.link("/robots.txt"))
# We actually can't find out is there robots.txt or not
# so we going to allow all in this case.
if self.state is False or self.state.allow_all:
return True
if not self.state.last_checked and self.state.disallow_all:
return False
# find entry
return allowed(matched_rules(self._entry(), url))
def request(self, url: str) -> None:
""" Perform robots.txt request """
if self.state is not None:
return
try:
self.state = RobotFileParser()
self.state.set_url(url)
self.state.read()
except Exception:
self.state = False
# This is mostly transferred logics from robotparser.py,
# but we trying to follow 2019 extension of the Google's Robots Txt
# protocol and allow, disallowed pathes.
# https://www.contentkingapp.com/blog/implications-of-new-robots-txt-rfc/
# https://tools.ietf.org/html/draft-koster-rep-04
def _entry(self) -> Any:
for entry in self.state.entries:
if entry.applies_to(user_agent):
return entry
return self.state.default_entry
def __init__(self, main_page=None, robotrules=True, threadcount=1):
"""ctor that checks args and decides to enable single or multithreaded
generation of sitemap
"""
logging.info("Consider Robot.txt ? ==> "+str(robotrules))
self.robotrules = robotrules
self.site_map = {}
self.unvisited = set([])
self.start_page = None
self.robot_txt_rules = None
if main_page:
self.unvisited.add(main_page)
try:
self.start_page = urlparse(main_page).netloc
except:
logging.error("Improper URL, Please provide a Valid Url:"+main_page)
exit(0)
if self.robotrules == "True":
try:
logging.info("robot.txt respected")
self.robot_txt_rules = RobotFileParser()
self.robot_txt_rules.set_url(main_page + "/robots.txt")
self.robot_txt_rules.read()
except:
logging.error("Unable to read the robot.txt file")
self.robotrules = False # error reading robot.txt, ignore it forever
self.threadcount = int(threadcount)
def __init__(self, database, fetcher, analyzer, verbose=False):
self.database = database
self.fetcher = fetcher
self.analyzer = analyzer
self.verbose = verbose
self.queue = set()
self.robot_parser = RobotFileParser()
def checkRobots(self):
if self.domain[len(self.domain)-1] != "/":
self.domain += "/"
request = Request(self.domain+"robots.txt", headers={"User-Agent":config.crawler_user_agent})
self.rp = RobotFileParser()
self.rp.set_url(self.domain+"robots.txt")
self.rp.read()
def rootFileParser():
rp = RobotFileParser()
rp.set_url("http://www.jianshu.com/robots.txt")
rp.read()
print(rp.can_fetch("*", "https://www.jianshu.com/p/b67554025d7d"))
print(
rp.can_fetch(
"*",
"http://www.jianshu.com/search?q=python&page=1&type=collections"))
def get_robots(self, url, download_handler):
robots_url = self._get_robots_url(url)
(robots_url_info, robots_url_content) = self._get_robots_content(
robots_url, download_handler)
if robots_url_content is None:
return None
content_type, ct_attrs = cgi.parse_header(
robots_url_info['content_type'])
charset = ct_attrs.get('charset', None)
if charset is None or charset == '':
charset = 'utf-8'
rf_parser = RobotFileParser()
rf_parser.parse(robots_url_content.decode(charset).splitlines())
return rf_parser
def robot_parse():
rp = RobotFileParser()
rp.set_url('http://www.jianshu.com/robots.txt')
rp.read()
print(rp.can_fetch('*', 'http://www.jianshu.com/p/'))
print(
rp.can_fetch(
'*',
"http://www.jianshu.com/search?q=python&page=1&type=collections"))
def set_url(): # 通过 set_url() 方法设置 robots.txt 的链接。
rp = RobotFileParser()
rp.set_url('http://www.bilibili.com/robots.txt')
rp.read()
# 使用 can_fetch() 方法判断网页是否可以被抓取。
print(rp.can_fetch('*', 'http://www.bilibili.com/vide/BV15J411T7WQ'))
print(
rp.can_fetch(
'*',
'http://www.bilibili.com/search?q=python&page=1&type=collections'))
def GetRobotsTxt(url):
rp = RobotFileParser()
rp.set_url(url)
rp.read()
print(
rp.can_fetch(
'*',
'https://book.douban.com/tag/?view=type&icn=index-sorttags-all'))
print(rp.can_fetch('*', 'https://book.douban.com/tag/%E5%B0%8F%E8%AF%B4'))
print(
rp.can_fetch(
'*',
'https://book.douban.com/tag/%E6%9D%91%E4%B8%8A%E6%98%A5%E6%A0%91?start=40&type=S'
))
def can_read(url):
domain = domain_name(url)
if domain not in Permissions:
rp = RobotFileParser()
rp.set_url(urljoin("http://" + domain, "robots.txt"))
try:
rp.read()
except:
return False
Permissions[domain] = rp
res = False
try:
res = Permissions[domain].can_fetch("*", url)
except:
return False
return res
def robotExclusion(link):
# print("Robot exclusion.....")
rp=RobotFileParser();
rp.set_url(urljoin(link, '/robot.txt'))
rp.read()
# print(rp.can_fetch("*", link))
return rp.can_fetch("*", link)
def check_robots_txt(self, parsed_link):
"""
Checks the site's robots.txt file to make sure our user agent is allowed to visit that url.
:param parsed_link:
:return: boolean . True if we're allowed to visit (or there's no robots.txt)
"""
rp = RobotFileParser()
rp.set_url(urljoin(parsed_link.geturl(), '/robots.txt'))
rp.read()
return rp.can_fetch(self.user_agent, parsed_link.geturl())
def is_scraping_allowed(self):
"""
Megnezi, hogy a robots.txt nem tiltja-e a scrapelest. Nem igazan teljes
az ellenorzes, mert csak az all job url-t vizsgalja.
:return:
"""
robot_parser = RobotFileParser()
robots_url = urljoin(self.base_url, 'robots.txt')
robot_parser.set_url(robots_url)
robot_parser.read()
return robot_parser.can_fetch('*', urljoin(
self.base_url, self.all_job_url))
def can_fetch_url(robots_url, site_url, useragent="*"):
"""
Using robots.txt found at robots_url, decides if useragent can fetch
site url
:param robots_url: robots.txt url
:param site_url: to be fetched url
:param useragent: useragent
:return: True, if fetching is allowed
"""
rfp = RobotFileParser()
rfp.set_url(robots_url)
rfp.read()
return rfp.can_fetch(useragent=useragent, url=site_url)
class SiteMap():
""" This class composes of all the functionalities needed to generate site_map"""
def __init__(self, main_page=None, robotrules=True, threadcount=1):
"""ctor that checks args and decides to enable single or multithreaded
generation of sitemap
"""
logging.info("Consider Robot.txt ? ==> "+str(robotrules))
self.robotrules = robotrules
self.site_map = {}
self.unvisited = set([])
self.start_page = None
self.robot_txt_rules = None
if main_page:
self.unvisited.add(main_page)
try:
self.start_page = urlparse(main_page).netloc
except:
logging.error("Improper URL, Please provide a Valid Url:"+main_page)
exit(0)
if self.robotrules == "True":
try:
logging.info("robot.txt respected")
self.robot_txt_rules = RobotFileParser()
self.robot_txt_rules.set_url(main_page + "/robots.txt")
self.robot_txt_rules.read()
except:
logging.error("Unable to read the robot.txt file")
self.robotrules = False # error reading robot.txt, ignore it forever
self.threadcount = int(threadcount)
def execute(self):
if self.threadcount <= 1: # if single threaded model is chosen, avoid threading
self.generate()
else:
self.start() # fasten by multi threads
def start(self):
"""This creates a pool of chosen limit so as to have the control and
spawns the main function and waits until process and subsequently
spawned process finish.
"""
self.pool = pool.Pool(self.threadcount)
self.pool.spawn(self.generate_parallels)
self.pool.join()
self.generate_reports()
def generate(self):
"""Non multithreaded model method that crawls until all pages are
crawled and assets are extracted. Once its done, it creates the
sitemap and assets json file for the given domain.
"""
while self.unvisited:
self.crawl()
self.generate_reports()
def generate_reports(self):
"""composes the xml tags with the keys in site_map member which are
nothing but the sitemap urls
"""
header = """<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:xhtml="http://www.w3.org/1999/xhtml"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
"""
footer = """\n</urlset>\n"""
entry = "\t<url><loc>%s</loc></url>\n"
xml = header
for url in self.site_map.keys():
xml += entry % (url)
xml += footer
name = self.start_page.replace(".", "_")
self.create_file("%s.xml" % (name), xml)
self.create_file("%s_assets.json" % (name), json.dumps(self.site_map, indent=2, sort_keys=True))
def generate_parallels(self):
"""
This method is similar to recursive in a way that crawls pages and clears
the queue, which is self.unvisited. It stops when there are no urls to crawl
and all threads in pool are empty i.e they are not active anymore due to
finishing of crawling. Since its spawning a new thread and not calling
directly, it is a nice way to go about it for now :)
[Note:] There is a limit for recursion in Python and it can be increased by
sys.setrecursionlimit(1500)
An assumption has been made for this implementation that a website that has
more than 500 nested links needs a bit higher design in terms to store the
assets which might go above a hundred MB. In such cases, this can just be
converted into a loop. More over, there is no extra stack variables.
"""
self.crawl()
while len(self.unvisited) > 0 and not self.pool.full():
self.pool.spawn(self.generate_parallels)
def create_file(self, file, content):
"""writes the given content to the file"""
f = open(file, 'w')
f.write(content)
f.close()
def compose_url_from_href(self, page, href):
"""composes a proper url from domainlink and intralinks with in the page"""
url = urlparse(page)
if href.startswith('/'):
return "http://%s%s"%(url.netloc, href)
elif href.startswith('#'):
return "http://%s%s%s"%(url.netloc, url.path, href)
elif href.startswith('./'):
return "http://%s%s"%(url.netloc, href[1:])
elif not href.startswith('http'):
return "http://" + url.netloc + '/' + href
elif href.endswith('/'):
return href[:-1]
return href
def get_out_going_links(self, page, html_body):
"""extracts all the outgoing links and adds links that belong to
main page domain for further crawling if they are not crawled yet
This avoids:
- links that are .zip files
- links mentioned in href that are javascript methods
- mailto: links
"""
soup = BeautifulSoup(html_body, "html.parser")
valid_links_for_this_page = []
for a in soup.find_all('a', href=True):
href = a['href'].lower()
href = self.compose_url_from_href(page, href)
# clean the href so that it will have legitimate urls instead of #cluttered ones and q=param prints
href = urldefrag(href)[0] # skip intra links [this took time to find out !] ##1
# remove query params as only the path matters
if href.find('?') != -1:
href = href[:href.find('?')] ##2
new_page = urlparse(href)
# add to the queue only it it doesn't cause a cycle
# assumption: if a link ends with domain.com, assuming it can be crawled to make sitemap complete
if not str(new_page.netloc).endswith(self.start_page): # doesn't belong to domain
valid_links_for_this_page.append(href)
continue
if self.robot_allows(href) and \
not href in self.site_map and \
not href in self.unvisited and \
not 'javascript:' in href and \
not 'mailto:' in href:
if not ( href.endswith(".zip") or
href.endswith(".gz") or
href.endswith(".gzip") or
href.endswith(".tar") or
href.endswith(".bz2") or
href.endswith(".jpg") or
href.endswith(".png") or
href.endswith(".exe")
):
self.unvisited.add(href)
valid_links_for_this_page.append(href)
return valid_links_for_this_page
def get_assets(self, page, headers, html_body):
"""A nice feature of response header is that it reports the last-modified
time of the link on the server. If we are doing regular crawling, we can
avoid if the link is not updates since the last time. This method is
useful for indexing the data so as to minimize the crawling effort to
save execution time.
It updates the site_map dictionary with the links, css, images and scripts
"""
if 'last-modified' in headers:
date = headers['Last-Modified']
else:
date = headers['Date']
soup = BeautifulSoup(html_body, "html.parser")
img = soup.findAll("img")
css = soup.findAll("link", {"rel": "stylesheet"})
js = soup.findAll('script')
self.site_map[page] = {
'date': date,
'links': self.get_out_going_links(page, html_body),
'css': [c['href'] for c in css],
'img': [i['src'] for i in img],
'js': [x.get('src', 'inline jscode') for x in js]
}
def crawl(self):
"""This actually opens the url and calls the assets method """
if len(self.unvisited) <= 0:
return
page = self.unvisited.pop()
if page in self.site_map:
return
logging.info("Starting to Crawl Page: " + page)
try:
response = self.access_page(page)
if (response.status_code != 200):
return None
html_body = response.text
self.get_assets(page, response.headers, html_body)
except:
logging.error("Issue while opening url: %s" + page)
return None
logging.debug("Crawled Pages: {}".format(len(self.site_map)))
def access_page(self, url):
"""accesses the url from the server. This method was created
to enable mock tests.
"""
return requests.get(url)
def get_site_map(self):
"""exposes site_map"""
return self.site_map
def set_start_page(self, url):
"""sets the start page for the crawler"""
self.start_page = url
def robot_allows(self, link):
"""method to check if link can be accessed as per robot rules"""
if not self.robotrules: return True
try:
if self.robot_txt_rules.can_fetch("*", link):
return True
return False
except:
return True
def __init__(self, scheduler, id): Thread.__init__(self) self.scheduler = scheduler self.robot_parser = RobotFileParser() self.running = True self.id = id
# Copyright(C) 2018 刘珅珅
# Environment: python 3.6.4
# Date: 2018.9.8
# robots协议测试
from urllib.robotparser import RobotFileParser
url = 'http://www.jianshu.com/robots.txt'
rp = RobotFileParser(url)
rp.read()
# 在scrapy中，如果希望爬取robots.txt禁止的页面，需要禁用robots
print(rp.can_fetch('*', 'http://www.jianshu.com/p/b67554025d7d')) # False，不允许爬取
def robot_can_fetch(robots_txt_content, url):
parser = RobotFileParser()
parser.parse(robots_txt_content.splitlines())
return parser.can_fetch(USER_AGENT, urlparse(url).path)
class Crawler():
# Variables
parserobots = False
output = None
report = False
config = None
domain = ""
exclude = []
skipext = []
drop = []
debug = False
tocrawl = set([])
crawled = set([])
excluded = set([])
marked = {}
not_parseable_ressources = (".epub", ".mobi", ".docx", ".doc", ".opf", ".7z", ".ibooks", ".cbr", ".avi", ".mkv", ".mp4", ".jpg", ".jpeg", ".png", ".gif" ,".pdf", ".iso", ".rar", ".tar", ".tgz", ".zip", ".dmg", ".exe")
# TODO also search for window.location={.*?}
linkregex = re.compile(b'<a [^>]*href=[\'|"](.*?)[\'"][^>]*?>')
imageregex = re.compile (b'<img [^>]*src=[\'|"](.*?)[\'"].*?>')
rp = None
response_code={}
nb_url=1 # Number of url.
nb_rp=0 # Number of url blocked by the robots.txt
nb_exclude=0 # Number of url excluded by extension or word
output_file = None
target_domain = ""
scheme = ""
def __init__(self, parserobots=False, output=None, report=False ,domain="",
exclude=[], skipext=[], drop=[], debug=False, verbose=False, images=False):
self.parserobots = parserobots
self.output = output
self.report = report
self.domain = domain
self.exclude = exclude
self.skipext = skipext
self.drop = drop
self.debug = debug
self.verbose = verbose
self.images = images
if self.debug:
log_level = logging.DEBUG
elif self.verbose:
log_level = logging.INFO
else:
log_level = logging.ERROR
logging.basicConfig(level=log_level)
self.tocrawl = set([self.clean_link(domain)])
try:
url_parsed = urlparse(domain)
self.target_domain = url_parsed.netloc
self.scheme = url_parsed.scheme
except:
logging.error("Invalide domain")
raise ("Invalid domain")
if self.output:
try:
self.output_file = open(self.output, 'w')
except:
logging.error ("Output file not available.")
exit(255)
def run(self):
print(config.xml_header, file=self.output_file)
if self.parserobots:
self.check_robots()
logging.info("Start the crawling process")
while len(self.tocrawl) != 0:
self.__crawling(first,domainname,all_link)
logging.info("Crawling has reached end of all found links")
print (config.xml_footer, file=self.output_file)
def __crawling(self,frst,dmname,all_links):
crawling = self.tocrawl.pop()
if frst==0:
dmname=obtaindomain(crawling)
frst=1
url = urlparse(crawling)
self.crawled.add(crawling)
logging.info("Crawling #{}: {}".format(len(self.crawled), url.geturl()))
request = Request(crawling, headers={"User-Agent":config.crawler_user_agent})
# Ignore ressources listed in the not_parseable_ressources
# Its avoid dowloading file like pdf… etc
if not url.path.endswith(self.not_parseable_ressources):
try:
response = urlopen(request)
except Exception as e:
if hasattr(e,'code'):
if e.code in self.response_code:
self.response_code[e.code]+=1
else:
self.response_code[e.code]=1
# Gestion des urls marked pour le reporting
if self.report:
if e.code in self.marked:
self.marked[e.code].append(crawling)
else:
self.marked[e.code] = [crawling]
logging.debug ("{1} ==> {0}".format(e, crawling))
return self.__continue_crawling()
else:
logging.debug("Ignore {0} content might be not parseable.".format(crawling))
response = None
# Read the response
if response is not None:
try:
msg = response.read()
if response.getcode() in self.response_code:
self.response_code[response.getcode()]+=1
else:
self.response_code[response.getcode()]=1
response.close()
# Get the last modify date
if 'last-modified' in response.headers:
date = response.headers['Last-Modified']
else:
date = response.headers['Date']
date = datetime.strptime(date, '%a, %d %b %Y %H:%M:%S %Z')
except Exception as e:
logging.debug ("{1} ===> {0}".format(e, crawling))
return None
else:
# Response is None, content not downloaded, just continu and add
# the link to the sitemap
msg = "".encode( )
date = None
# Image sitemap enabled ?
image_list = "";
if self.images:
# Search for images in the current page.
images = self.imageregex.findall(msg)
for image_link in list(set(images)):
image_link = image_link.decode("utf-8", errors="ignore")
# Ignore link starting with data:
if image_link.startswith("data:"):
continue
# If path start with // get the current url scheme
if image_link.startswith("//"):
image_link = url.scheme + ":" + image_link
# Append domain if not present
elif not image_link.startswith(("http", "https")):
if not image_link.startswith("/"):
image_link = "/{0}".format(image_link)
image_link = "{0}{1}".format(self.domain.strip("/"), image_link.replace("./", "/"))
# Ignore image if path is in the exclude_url list
if not self.exclude_url(image_link):
continue
# Ignore other domain images
image_link_parsed = urlparse(image_link)
if image_link_parsed.netloc != self.target_domain:
continue
# Test if images as been already seen and not present in the
# robot file
if self.can_fetch(image_link):
logging.debug("Found image : {0}".format(image_link))
image_list = "{0}<image:image><image:loc>{1}</image:loc></image:image>".format(image_list, self.htmlspecialchars(image_link))
# Last mod fetched ?
lastmod = ""
if date:
lastmod = "<lastmod>"+date.strftime('%Y-%m-%dT%H:%M:%S+00:00')+"</lastmod>"
print ("<url><loc>"+self.htmlspecialchars(url.geturl())+"</loc>" + lastmod + image_list + "</url>", file=self.output_file)
tempdom=obtaindomain(self.htmlspecialchars(url.geturl()))
templink=self.htmlspecialchars(url.geturl())
if tempdom==dmname:
if templink not in all_links:
outputprint(templink)
all_links.append(templink)
if self.output_file:
self.output_file.flush()
# Found links
links = self.linkregex.findall(msg)
for link in links:
link = link.decode("utf-8", errors="ignore")
link = self.clean_link(link)
logging.debug("Found : {0}".format(link))
if link.startswith('/'):
link = url.scheme + '://' + url[1] + link
elif link.startswith('#'):
link = url.scheme + '://' + url[1] + url[2] + link
elif link.startswith(("mailto", "tel")):
continue
elif not link.startswith(('http', "https")):
link = url.scheme + '://' + url[1] + '/' + link
# Remove the anchor part if needed
if "#" in link:
link = link[:link.index('#')]
# Drop attributes if needed
for toDrop in self.drop:
link=re.sub(toDrop,'',link)
# Parse the url to get domain and file extension
parsed_link = urlparse(link)
domain_link = parsed_link.netloc
target_extension = os.path.splitext(parsed_link.path)[1][1:]
if link in self.crawled:
continue
if link in self.tocrawl:
continue
if link in self.excluded:
continue
if domain_link != self.target_domain:
continue
if parsed_link.path in ["", "/"]:
continue
if "javascript" in link:
continue
if self.is_image(parsed_link.path):
continue
if parsed_link.path.startswith("data:"):
continue
# Count one more URL
self.nb_url+=1
# Check if the navigation is allowed by the robots.txt
if not self.can_fetch(link):
self.exclude_link(link)
self.nb_rp+=1
continue
# Check if the current file extension is allowed or not.
if (target_extension in self.skipext):
self.exclude_link(link)
self.nb_exclude+=1
continue
# Check if the current url doesn't contain an excluded word
if (not self.exclude_url(link)):
self.exclude_link(link)
self.nb_exclude+=1
continue
self.tocrawl.add(link)
return None
def clean_link(self, link):
l = urlparse(link)
l_res = list(l)
l_res[2] = l_res[2].replace("./", "/")
l_res[2] = l_res[2].replace("//", "/")
return urlunparse(l_res)
def is_image(self, path):
mt,me = mimetypes.guess_type(path)
return mt is not None and mt.startswith("image/")
def __continue_crawling(self):
if self.tocrawl:
self.__crawling(first,domainname,all_link)
def exclude_link(self,link):
if link not in self.excluded:
self.excluded.add(link)
def check_robots(self):
robots_url = urljoin(self.domain, "robots.txt")
self.rp = RobotFileParser()
self.rp.set_url(robots_url)
self.rp.read()
def can_fetch(self, link):
try:
if self.parserobots:
if self.rp.can_fetch("*", link):
return True
else:
logging.debug ("Crawling of {0} disabled by robots.txt".format(link))
return False
if not self.parserobots:
return True
return True
except:
# On error continue!
logging.debug ("Error during parsing robots.txt")
return True
def exclude_url(self, link):
for ex in self.exclude:
if ex in link:
return False
return True
def htmlspecialchars(self, text):
return text.replace("&", "&").replace('"', """).replace("<", "<").replace(">", ">")
def make_report(self):
print ("Number of found URL : {0}".format(self.nb_url))
print ("Number of link crawled : {0}".format(len(self.crawled)))
if self.parserobots:
print ("Number of link block by robots.txt : {0}".format(self.nb_rp))
if self.skipext or self.exclude:
print ("Number of link exclude : {0}".format(self.nb_exclude))
for code in self.response_code:
print ("Nb Code HTTP {0} : {1}".format(code, self.response_code[code]))
for code in self.marked:
print ("Link with status {0}:".format(code))
for uri in self.marked[code]:
print ("\t- {0}".format(uri))
class _RobotAllowAll:
def can_fetch(self, a,b):
return True
class Robot:
def __init__(self):
self.__robots = {}
def can_fetch(self, url):
parse = urllib.parse.urlparse(url)
hostname = parse.hostname
try:
robot = self.robot[hostname]
except Exception:
roboturl = urllib.parse.urlunparse((parse.scheme,parse.netloc,"robots.txt","","",""))
robot = RobotFileParser(roboturl)
try:
robot.read()
except Exception:
robot = _RobotAllowAll()
self.__robots[hostname] = robot
return robot.can_fetch("*", url)
if __name__ == "__main__":
r = RobotFileParser("http://www.letudiant.fr", {})
r.read()
print(r.can_fetch("*", "http://www.letudiant.fr/"))
class Crawler():
# Variables
parserobots = False
output = None
report = False
config = None
domain = ""
exclude = []
skipext = []
drop = []
debug = False
tocrawl = set([])
crawled = set([])
excluded = set([])
# TODO also search for window.location={.*?}
linkregex = re.compile(b'<a href=[\'|"](.*?)[\'"].*?>')
rp = None
response_code={}
nb_url=1 # Number of url.
nb_rp=0 # Number of url blocked by the robots.txt
nb_exclude=0 # Number of url excluded by extension or word
output_file = None
target_domain = ""
def __init__(self, parserobots=False, output=None, report=False ,domain="", exclude=[], skipext=[], drop=[], debug=False):
self.parserobots = parserobots
self.output = output
self.report = report
self.domain = domain
self.exclude = exclude
self.skipext = skipext
self.drop = drop
self.debug = debug
if self.debug:
logging.basicConfig(level=logging.DEBUG)
self.tocrawl = set([domain])
try:
self.target_domain = urlparse(domain)[1]
except:
raise ("Invalid domain")
if self.output:
try:
self.output_file = open(self.output, 'w')
except:
logging.debug ("Output file not available.")
exit(255)
def run(self):
print (config.xml_header, file=self.output_file)
logging.debug("Start the crawling process")
self.__crawling()
logging.debug("Crawling as reach the end of all found link")
print (config.xml_footer, file=self.output_file)
def __crawling(self):
crawling = self.tocrawl.pop()
url = urlparse(crawling)
self.crawled.add(crawling)
request = Request(crawling, headers={"User-Agent":config.crawler_user_agent})
try:
response = urlopen(request)
except Exception as e:
if hasattr(e,'code'):
if e.code in self.response_code:
self.response_code[e.code]+=1
else:
self.response_code[e.code]=1
logging.debug ("{1} ==> {0}".format(e, crawling))
return self.__continue_crawling()
# Read the response
try:
msg = response.read()
if response.getcode() in self.response_code:
self.response_code[response.getcode()]+=1
else:
self.response_code[response.getcode()]=1
response.close()
# Get the last modify date
if 'last-modified' in response.headers:
date = response.headers['Last-Modified']
else:
date = response.headers['Date']
date = datetime.strptime(date, '%a, %d %b %Y %H:%M:%S %Z')
except Exception as e:
logging.debug ("{1} ===> {0}".format(e, crawling))
return self.__continue_crawling()
print ("<url><loc>"+url.geturl()+"</loc><lastmod>"+date.strftime('%Y-%m-%dT%H:%M:%S')+"</lastmod></url>", file=self.output_file)
if self.output_file:
self.output_file.flush()
# Found links
links = self.linkregex.findall(msg)
for link in links:
link = link.decode("utf-8")
#logging.debug("Found : {0}".format(link))
if link.startswith('/'):
link = 'http://' + url[1] + link
elif link.startswith('#'):
link = 'http://' + url[1] + url[2] + link
elif not link.startswith('http'):
link = 'http://' + url[1] + '/' + link
# Remove the anchor part if needed
if "#" in link:
link = link[:link.index('#')]
# Drop attributes if needed
for toDrop in self.drop:
link=re.sub(toDrop,'',link)
# Parse the url to get domain and file extension
parsed_link = urlparse(link)
domain_link = parsed_link.netloc
target_extension = os.path.splitext(parsed_link.path)[1][1:]
if (link in self.crawled):
continue
if (link in self.tocrawl):
continue
if (link in self.excluded):
continue
if (domain_link != self.target_domain):
continue
if ("javascript" in link):
continue
# Count one more URL
self.nb_url+=1
# Check if the navigation is allowed by the robots.txt
if (not self.can_fetch(link)):
self.exclude_link(link)
self.nb_rp+=1
continue
# Check if the current file extension is allowed or not.
if (target_extension in self.skipext):
self.exclude_link(link)
self.nb_exclude+=1
continue
# Check if the current url doesn't contain an excluded word
if (not self.exclude_url(link)):
self.exclude_link(link)
self.nb_exclude+=1
continue
self.tocrawl.add(link)
return self.__continue_crawling()
def __continue_crawling(self):
if self.tocrawl:
self.__crawling()
def exclude_link(self,link):
if link not in self.excluded:
self.excluded.add(link)
def checkRobots(self):
if self.domain[len(self.domain)-1] != "/":
self.domain += "/"
request = Request(self.domain+"robots.txt", headers={"User-Agent":config.crawler_user_agent})
self.rp = RobotFileParser()
self.rp.set_url(self.domain+"robots.txt")
self.rp.read()
def can_fetch(self, link):
try:
if self.parserobots:
if self.rp.can_fetch("*", link):
return True
else:
logging.debug ("Crawling of {0} disabled by robots.txt".format(link))
return False
if not self.parserobots:
return True
return True
except:
# On error continue!
logging.debug ("Error during parsing robots.txt")
return True
def exclude_url(self, link):
for ex in self.exclude:
if ex in link:
return False
return True
def make_report(self):
print ("Number of found URL : {0}".format(self.nb_url))
print ("Number of link crawled : {0}".format(len(self.crawled)))
if self.parserobots:
print ("Number of link block by robots.txt : {0}".format(self.nb_rp))
if self.skipext or self.exclude:
print ("Number of link exclude : {0}".format(self.nb_exclude))
for code in self.response_code:
print ("Nb Code HTTP {0} : {1}".format(code, self.response_code[code]))
def check_robots(self): robots_url = urljoin(self.domain, "robots.txt") self.rp = RobotFileParser() self.rp.set_url(robots_url) self.rp.read()
def _get_robot_parser(self):
parser = RobotFileParser()
parser.set_url(self.protocol + "://" + self.domain + "/robots.txt")
return parser
class Crawler(object):
def __init__(self, database, fetcher, analyzer, verbose=False):
self.database = database
self.fetcher = fetcher
self.analyzer = analyzer
self.verbose = verbose
self.queue = set()
self.robot_parser = RobotFileParser()
def crawl(self, url):
"""Begin recursively crawling pages starting from the given URL.
:param url: Starting URL
:returns: None
"""
if self.database.is_page_stored(url):
print("Page is already crawled. Use --flush to flush the database file.", file=sys.stderr)
else:
# Because crawling is restricted to pages on the same domain, the
# robots.txt file can be loaded once at the beginning of the crawl
self.load_robots_file(url)
# Add the starting URL to the queue of pages to be crawled, and
# then keep crawling while there are still URLs in the queue
self.queue.add(url)
while len(self.queue) > 0:
self.crawl_one(self.queue.pop())
def crawl_one(self, url):
"""Fetch a single page and analyze it for links. The found triples are
stored in the database, and found links that should be crawled are
added to the queue.
:param url: The page to fetch and analyze
:returns: None
"""
if self.verbose:
print(url, file=sys.stderr)
status, html = self.fetcher.fetch(url)
if status is None:
# The status code will be None if retrieval failed
print("Failed to get {}".format(url), file=sys.stderr)
else:
# Search for links and images in the page, and get them as triples
# of (page URL, link type, link URL)
triples = self.analyzer.analyze(url, html)
self.database.store_triples(triples)
# Any linked URLs that are eligible for crawling are added to the
# pending crawl queue
for page_url, link_type, link_url in triples:
if self.should_crawl(page_url, link_type, link_url):
self.queue.add(link_url)
def should_crawl(self, page_url, link_type, link_url):
"""Determine whether a URL should be crawled.
:param page_url: The page the link came from.
:param link_type: The type of link URL.
:param link_url: The link URL to test.
:returns: True if the link URL should be crawled, otherwise False.
"""
# Only HTML pages should be crawled, not other media
if link_type not in ('page', 'iframe'):
return False
# The link should be on the same domain as the page it's linked from
if not self.have_same_domain(page_url, link_url):
return False
# Fetching the link URL should be permitted by robots.txt
if not self.robot_parser.can_fetch('Cosmo', link_url):
return False
# The linked page should not have been crawled already
if self.database.is_page_stored(link_url):
return False
return True
def have_same_domain(self, url1, url2):
"""Test whether two URLs have the same hostname and port.
:returns: True if they do, otherwise False
"""
return urlparse(url1).netloc == urlparse(url2).netloc
def load_robots_file(self, url):
"""Load the /robots.txt file for the given URL by reusing the scheme
and authority parts.
:param url: The URL from which to take the scheme and authority parts.
:returns: None
"""
# Create a new URL with the same scheme, host and port, but with a
# path of /robots.txt
parsed = urlparse(url)
robots_url = urlunparse((parsed.scheme, parsed.netloc, '/robots.txt', '', '', ''))
# Load the robots.txt file using the requests library, because we need
# to specify the User-Agent header. I noticed on a CloudFlare-fronted
# site that it returns a 403 for /robots.txt if the the user agent is
# Python-urllib, but 200 if it's Cosmo.
status, robots_file = self.fetcher.fetch(robots_url)
if status in (401, 403):
self.robot_parser.disallow_all = True
elif status >= 400:
self.robot_parser.allow_all = True
else:
self.robot_parser.parse(robots_file.splitlines())
