Python爬虫获取整个站点中的所有外部链接代码示例_Python

收集所有外部链接的网站爬虫程序流程图

Python爬虫获取整个站点中的所有外部链接代码示例

下例是爬取本站python绘制条形图方法代码详解的实例，大家可以参考下。

完整代码：

									#! /usr/bin/env python

									#coding=utf-8

									import urllib2

									from  bs4 import BeautifulSoup

									import re

									import datetime

									import random

									pages=set()

									random.seed(datetime.datetime.now())

									#Retrieves a list of all Internal links found on a page

									def getInternalLinks(bsObj, includeUrl):

									        internalLinks  =  []

									        #Finds all links  that  begin  with  a  "/"

									        for link  in bsObj.findAll("a", href=re.compile("^(/|.*"+includeUrl+")")):

									                if link.attrs['href'] is not None:

									                        if link.attrs['href'] not in internalLinks:

									                                internalLinks.append(link.attrs['href'])

									        return internalLinks

									#Retrieves a list of all external links found on a page

									def getExternalLinks(bsObj, excludeUrl):

									        externalLinks  =  []

									        #Finds all links  that  start  with  "http" or "www"  that  do

									        #not  contain the current URL

									        for link  in bsObj.findAll("a", 

									                              href=re.compile("^(http|www)((?!"+excludeUrl+").)*$")):

									                if link.attrs['href'] is not None:

									                        if link.attrs['href'] not in externalLinks:

									                                externalLinks.append(link.attrs['href'])

									        return externalLinks

									def splitAddress(address):

									        addressParts  =  address.replace("http://", "").split("/")

									        return addressParts

									def getRandomExternalLink(startingPage):

									        html=  urllib2.urlopen(startingPage)

									        bsObj  =  BeautifulSoup(html)

									        externalLinks  =  getExternalLinks(bsObj, splitAddress(startingPage)[0])

									        if len(externalLinks) == 0:

									                internalLinks  =  getInternalLinks(startingPage)

									                return internalLinks[random.randint(0, len(internalLinks)-1)]

									        else:

									                return externalLinks[random.randint(0, len(externalLinks)-1)]

									def followExternalOnly(startingSite):

									        externalLink=getRandomExternalLink("//www.zyiz.net/article/130968.htm")

									        print("Random  external  link  is: "+externalLink)

									        followExternalOnly(externalLink)

									#Collects a list of all external URLs found on the site

									allExtLinks=set()

									allIntLinks=set()

									def getAllExternalLinks(siteUrl):

									    html=urllib2.urlopen(siteUrl)

									    bsObj=BeautifulSoup(html)

									    internalLinks  =  getInternalLinks(bsObj,splitAddress(siteUrl)[0])

									    externalLinks  =  getExternalLinks(bsObj,splitAddress(siteUrl)[0])

									    for link in externalLinks:

									      if link not in allExtLinks:

									        allExtLinks.add(link)

									        print(link)

									    for link in internalLinks:

									      if link not in allIntLinks:

									        print("About to get link:"+link)

									        allIntLinks.add(link)

									        getAllExternalLinks(link)

									getAllExternalLinks("//www.zyiz.net/article/130968.htm")

爬取结果如下：

Python爬虫获取整个站点中的所有外部链接代码示例

总结

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原文链接：http://blog.csdn.net/qq_16103331/article/details/52690558

Python爬虫获取整个站点中的所有外部链接代码示例

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