你見過哪些令你瞠目結舌的爬蟲技巧？

import time
from datetime import timedelta
from tornado import httpclient, gen, ioloop, queues
import traceback

class AsySpider(object):
"""A simple class of asynchronous spider."""
def __init__(self, urls, concurrency=10, results=None, **kwargs):
urls.reverse()
self.urls = urls
self.concurrency = concurrency
self._q = queues.Queue()
self._fetching = set()
self._fetched = set()
if results is None:
self.results = []

def fetch(self, url, **kwargs):
fetch = getattr(httpclient.AsyncHTTPClient(), "fetch")
return fetch(url, raise_error=False, **kwargs)

def handle_html(self, url, html):
"""handle html page"""
print(url)

def handle_response(self, url, response):
"""inherit and rewrite this method if necessary"""
if response.code == 200:
self.handle_html(url, response.body)

elif response.code == 599: # retry
self._fetching.remove(url)
self._q.put(url)

@gen.coroutine
def get_page(self, url):
try:
response = yield self.fetch(url)
#print("######fetched %s" % url)
except Exception as e:
print("Exception: %s %s" % (e, url))
raise gen.Return(e)
raise gen.Return(response)

@gen.coroutine
def _run(self):
@gen.coroutine
def fetch_url():
current_url = yield self._q.get()
try:
if current_url in self._fetching:
return

#print("fetching****** %s" % current_url)
self._fetching.add(current_url)

response = yield self.get_page(current_url)
self.handle_response(current_url, response) # handle reponse

self._fetched.add(current_url)

for i in range(self.concurrency):
if self.urls:
yield self._q.put(self.urls.pop())

finally:
self._q.task_done()

@gen.coroutine
def worker():
while True:
yield fetch_url()

self._q.put(self.urls.pop()) # add first url

# Start workers, then wait for the work queue to be empty.
for _ in range(self.concurrency):
worker()

yield self._q.join(timeout=timedelta(seconds=300000))
try:
assert self._fetching == self._fetched
except AssertionError:
print(self._fetching-self._fetched)
print(self._fetched-self._fetching)

def run(self):
io_loop = ioloop.IOLoop.current()
io_loop.run_sync(self._run)

class MySpider(AsySpider):

def fetch(self, url, **kwargs):
"""重寫父類fetch方法可以添加cookies，headers，timeout等信息"""
cookies_str = "PHPSESSID=j1tt66a829idnms56ppb70jri4; pspt=%7B%22id%22%3A%2233153%22%2C%22pswd%22%3A%228835d2c1351d221b4ab016fbf9e8253f%22%2C%22_code%22%3A%22f779dcd011f4e2581c716d1e1b945861%22%7D; key=%E9%87%8D%E5%BA%86%E5%95%84%E6%9C%A8%E9%B8%9F%E7%BD%91%E7%BB%9C%E7%A7%91%E6%8A%80%E6%9C%89%E9%99%90%E5%85%AC%E5%8F%B8; think_language=zh-cn; SERVERID=a66d7d08fa1c8b2e37dbdc6ffff82d9e|1444973193|1444967835; CNZZDATA1254842228=1433864393-1442810831-%7C1444972138"
headers = {
"User-Agent": "mozilla/5.0 (compatible; baiduspider/2.0; +http://www.baidu.com/search/spider.html)",
"cookie": cookies_str
}
return super(MySpider, self).fetch(
url, headers=headers
)

def handle_html(self, url, html):
#print(url, html)
print(url)

def main():
urls = []
for page in range(1, 10000):
urls.append("http://www.baidu.com/?page=%s" % page)
s = MySpider(urls)
s.run()