Python web爬虫:连接超时
我正在尝试实现一个简单的web爬虫程序,我已经编写了一个简单的代码开始:有两个模块fetcher.py和crawler.py。以下是文件: fetcher.py:Python web爬虫:连接超时,python,web-crawler,beautifulsoup,Python,Web Crawler,Beautifulsoup,我正在尝试实现一个简单的web爬虫程序,我已经编写了一个简单的代码开始:有两个模块fetcher.py和crawler.py。以下是文件: fetcher.py: import urllib2 import re def fetcher(s): "fetch a web page from a url" try: req = urllib2.Request(s) urlResponse = urllib2.
import urllib2
import re
def fetcher(s):
"fetch a web page from a url"
try:
req = urllib2.Request(s)
urlResponse = urllib2.urlopen(req).read()
except urllib2.URLError as e:
print e.reason
return
p,q = s.split("//")
d = q.split("/")
fdes = open(d[0],"w+")
fdes.write(str(urlResponse))
fdes.seek(0)
return fdes
if __name__ == "__main__":
defaultSeed = "http://www.python.org"
print fetcher(defaultSeed)
crawler.py:
from bs4 import BeautifulSoup
import re
from fetchpage import fetcher
usedLinks = open("Used","a+")
newLinks = open("New","w+")
newLinks.seek(0)
def parse(fd,var=0):
soup = BeautifulSoup(fd)
for li in soup.find_all("a",href=re.compile("http")):
newLinks.seek(0,2)
newLinks.write(str(li.get("href")).strip("/"))
newLinks.write("\n")
fd.close()
newLinks.seek(var)
link = newLinks.readline().strip("\n")
return str(link)
def crawler(seed,n):
if n == 0:
usedLinks.close()
newLinks.close()
return
else:
usedLinks.write(seed)
usedLinks.write("\n")
fdes = fetcher(seed)
newSeed = parse(fdes,newLinks.tell())
crawler(newSeed,n-1)
if __name__ == "__main__":
crawler("http://www.python.org/",7)
问题是,当我运行crawler.py时,它在前4-5个链接中工作正常,然后它挂起,一分钟后会出现以下错误:
[Errno 110] Connection timed out
Traceback (most recent call last):
File "crawler.py", line 37, in <module>
crawler("http://www.python.org/",7)
File "crawler.py", line 34, in crawler
crawler(newSeed,n-1)
File "crawler.py", line 34, in crawler
crawler(newSeed,n-1)
File "crawler.py", line 34, in crawler
crawler(newSeed,n-1)
File "crawler.py", line 34, in crawler
crawler(newSeed,n-1)
File "crawler.py", line 34, in crawler
crawler(newSeed,n-1)
File "crawler.py", line 33, in crawler
newSeed = parse(fdes,newLinks.tell())
File "crawler.py", line 11, in parse
soup = BeautifulSoup(fd)
File "/usr/lib/python2.7/dist-packages/bs4/__init__.py", line 169, in __init__
self.builder.prepare_markup(markup, from_encoding))
File "/usr/lib/python2.7/dist-packages/bs4/builder/_lxml.py", line 68, in prepare_markup
dammit = UnicodeDammit(markup, try_encodings, is_html=True)
File "/usr/lib/python2.7/dist-packages/bs4/dammit.py", line 191, in __init__
self._detectEncoding(markup, is_html)
File "/usr/lib/python2.7/dist-packages/bs4/dammit.py", line 362, in _detectEncoding
xml_encoding_match = xml_encoding_re.match(xml_data)
TypeError: expected string or buffer
[Errno 110]连接超时
回溯(最近一次呼叫最后一次):
文件“crawler.py”,第37行,在
爬虫(“http://www.python.org/",7)
文件“crawler.py”,第34行,在crawler中
爬虫机(新闻种子,n-1)
文件“crawler.py”,第34行,在crawler中
爬虫机(新闻种子,n-1)
文件“crawler.py”,第34行,在crawler中
爬虫机(新闻种子,n-1)
文件“crawler.py”,第34行,在crawler中
爬虫机(新闻种子,n-1)
文件“crawler.py”,第34行,在crawler中
爬虫机(新闻种子,n-1)
文件“crawler.py”,第33行,在crawler中
newSeed=parse(fdes,newLinks.tell())
解析中第11行的文件“crawler.py”
汤=美汤(fd)
文件“/usr/lib/python2.7/dist-packages/bs4/_-init___;.py”,第169行,在__-init中__
self.builder.prepare_标记(标记,来自_编码))
文件“/usr/lib/python2.7/dist packages/bs4/builder/_lxml.py”,第68行,在准备标记中
dammit=UnicodeAmmit(标记,尝试编码,是html=True)
文件“/usr/lib/python2.7/dist packages/bs4/dammit.py”,第191行,在__
self.\u detectEncoding(标记,即html)
文件“/usr/lib/python2.7/dist packages/bs4/dammit.py”,第362行,in_detectEncoding
xml\u encoding\u match=xml\u encoding\u re.match(xml\u数据)
TypeError:应为字符串或缓冲区
有人能帮我吗?我对python非常陌生,我不知道为什么说连接超时了一段时间后?A不是python特有的,它只是意味着您向服务器发出了请求,而服务器在您的应用程序愿意等待的时间内没有响应
发生这种情况的一个很可能的原因是python.org可能有某种机制来检测它何时从脚本获取多个请求,并且可能在4-5个请求之后完全停止服务页面。除了在另一个站点上尝试脚本之外,您实在无法避免这种情况。您可以尝试使用代理来避免在上述多个请求中被检测到。您可能想查看这个答案,了解如何使用代理发送urllib请求:是。每次链接的确切数量后,它就会被卡住。我在其他网站上运行了相同的脚本,但它没有给我这个问题。:)谢谢你的回复。