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最近总是要爬取一些东西，索性就把Python爬虫的相关内容都总结起来了，自己多动手还是好。（1）普通的内容爬取
#coding=utf-8
import urllib
import urllib2
url = 'http://www.dataanswer.top'
headers = {
'Host':'www.dataanswer.top',
'User-Agent':'Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:31.0) Gecko/20100101 Firefox/31.0',
#'Accept':'application/json, text/javascript, */*; q=0.01',
#'Accept-Language':'zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3',
#'Accept-Encoding':'gzip,deflate',
#'Referer':'http://www.dataanswer.top'
}
request = urllib2.Request(url,headers=headers)
response = urllib2.urlopen(request)
page = response.read()
print page二，保存爬取的图片/视频和文件和网页#coding=utf-8
import urllib
import urllib2
import os
def getPage(url):
request = urllib2.Request(url)
response = urllib2.urlopen(request)
return response.read()
url='http://www.dataanswer.top/'
result=getPage(url)
file_name='test.doc'
file_path='doc'
if os.path.exists(file_path) == False:
os.makedirs(file_path)
local=os.path.join(file_path,file_name)
f = open(local,"w+")
f.write(result)
f.close()
#coding=utf-8
import urllib
import urllib2
import os
def getPage(url):
request = urllib2.Request(url)
response = urllib2.urlopen(request)
return response.read()
url='http://www.dataanswer.top/' #把该地址改成图片/文件/视频/网页的地址即可
result=getPage(url)
file_name='test.doc'
file_path='doc'
if os.path.exists(file_path) == False:
os.makedirs(file_path)
local=os.path.join(file_path,file_name)
urllib.urlretrieve(local)三,普通模拟登录import urllib
import urllib2
import cookielib
filename = 'cookie.txt'
#声明一个MozillaCookieJar对象实例来保存cookie，之后写入文件
cookie = cookielib.MozillaCookieJar(filename)
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookie))
postdata = urllib.urlencode({
'name':'春天里',
'pwd':'1222222'
})
#登录的URL
loginUrl = 'http://www.dataanswer.top/LoginService?action=tologin'
#模拟登录，并把cookie保存到变量
result = opener.open(loginUrl,postdata)
#保存cookie到cookie.txt中
cookie.save(ignore_discard=True, ignore_expires=True)
#利用cookie请求访问另一个网址
gradeUrl = 'http://www.dataanswer.top/LoginService?action=myHome'
#请求访问
result = opener.open(gradeUrl)
print result.read()四，处理验证码登录#coding=utf-8
import sys, time, os, re
import urllib, urllib2, cookielib
loginurl = 'https://www.douban.com/accounts/login'
cookie = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookie))
params = {
"form_email":"13161055481",
"form_password":"wwwwwww",
"source":"index_nav" #没有的话登录不成功
}
#从首页提交登录
response=opener.open(loginurl)
#验证成功跳转至登录页
print(response.geturl())
if response.geturl() == "https://www.douban.com/accounts/login":
html=response.read()
print(html)
#验证码图片地址--图片地址加密怎么办？？？
imgurl=re.search('<img id="captcha_image" src="(.+?)" alt="captcha" class="captcha_image"/>', html)
print(imgurl)
if imgurl:
url=imgurl.group(1)
#将图片保存至同目录下
res=urllib.urlretrieve(url,'v.jpg')
#获取captcha-id参数
captcha=re.search('<input type="hidden" name="captcha-id" value="(.+?)"/>',html)
if captcha:
vcode=raw_input('请输入图片上的验证码：')
params["captcha-solution"]=vcode
params["captcha-id"]=captcha.group(1)
params["user_login"]="登录"
#提交验证码验证
response=opener.open(loginurl, urllib.urlencode(params))
''' 登录成功跳转至首页 '''
if response.geturl() == "https://www.douban.com/":
print 'login success ! '
print '准备进行发帖'
addtopicurl="http://www.douban.com/group/python/new_topic"
res=opener.open(addtopicurl)
html=res.read()
else:
print("Fail3")
else:
print("Fail2")
else:
print("Fail1")
else:
print("Fail0")五，爬取js网站#coding=utf-8
#1、安装 python-pip
#sudo apt-get install python-pip
#2、安装selenium
#sudo pip install -U selenium
from selenium import webdriver
driver = webdriver.Firefox()
driver.get('http://www.newsmth.net/nForum/#!article/Intern/206790')
html=driver.page_source.encode('utf-8','ignore') #这个函数获取页面的html
print(html)
driver.close()#coding=utf-8
"""
全网爬取所有链接，包括外链--广度优先
"""
import urllib2
import re
from bs4 import BeautifulSoup
import time
#爬虫开始的时间
t=time.time()
#设置的暂停爬取条数
N_STOP=10
#存放已经爬取过的url
CHECKED_URL=[]
#存放待爬取的url
CHECKING_URL=[]
#存放连接失败的url
FAIL_URL=[]
#存放不能连接的url
ERROR_URL=[]
#失败后允许连接的次数
RETRY=3
#连接超时时间
TIMEOUT=20
class url_node:
def __init__(self,url):
"""
url节点初始化
：param url:String 当前url
"""
self.url=url
self.content=''
def __is_connectable(self):
"""
检验url是否可以连接
"""
#在允许连接次数下连接
for i in range(RETRY):
try:
#打开url没有报错，则表示可连接
response=urllib2.urlopen(self.url,timeout=TIMEOUT)
return True
except:
#如果在尝试允许连接次数下报错，则不可连接
if i==RETRY-1:
return False
def get_next(self):
"""
获取爬取该页中包含的其他所有的url
"""
soup=BeautifulSoup(self.content)
#******************在此处可以从网页中解析你想要的内容************************************
next_urls=soup.findAll('a')
if len(next_urls)!=0:
for link in next_urls:
tmp_url=link.get('href')
#如果url不在爬取过的列表中也不在待爬取列表中则把其放到待爬列表中（没有确保该url有效）
if tmp_url not in CHECKED_URL and tmp_url not in CHECKING_URL:
CHECKING_URL.append(tmp_url)
def run(self):
if self.url:
if self.__is_connectable():
try:
#获取爬取页面的所有内容
self.content=urllib2.urlopen(self.url,timeout=TIMEOUT).read()
#从该页面中获取url
self.get_next()
except:
#把连接失败的存放起来
FAIL_URL.append(self.url)
print('[!]Connect Failed')
else:
#把不能连接的存放起来
ERROR_URL.append(self.url)
else:
print("所给的初始url有问题！")
if __name__=='__main__':
#把初始的url放到待爬的列表中
CHECKING_URL.append('http://www.36dsj.com/')
#不断的从待爬的列表中获取url进行爬取
ff=open("Mytest.txt",'w')
i=0
for url in CHECKING_URL:
#对该url进行爬取
url_node(url).run()
#存放已经爬取过的url
CHECKED_URL.append(url)
#删除CHECKING_URL中已经爬取过的url
CHECKING_URL.remove(url)
i+=1
if i==N_STOP:
#打出停止时的url，下次可以把该url作为初始继续
print url
print("爬取过的列表长度：%d") % len(CHECKED_URL)
print("待爬取的列表长度：%d") % len(CHECKING_URL)
print("连接失败的列表长度：%d") % len(FAIL_URL)
print("不能连接的列表长度：%d") % len(ERROR_URL)
break
ff.close()
print("time:%d s") % (time.time()-t) #coding=utf-8
"""
爬取同一个网站所有的url,不包括外链
"""
import urllib2
import re
from bs4 import BeautifulSoup
import time
t=time.time()
HOST=''
CHECKED_URL=[]
CHECKING_URL=[]
RESULT=[]
RETRY=3
TIMEOUT=20
class url_node:
def __init__(self,url):
"""
url节点初始化
：param url:String 当前url
"""
self.url=self.handle_url(url,is_next_url=False)
self.next_url=[]
self.content=''
def handle_url(self,url,is_next_url=True):
"""
将所有的url处理成标准形式
"""
global CHECKED_URL
global CHECKING_URL
#去掉尾部的‘/’
url=url[0:len(url)-1] if url.endswith('/') else url
if url.find(HOST)==-1:
if not url.startswith('http'):
url='http://'+HOST+url if url.startswith('/') else 'http://'+HOST+'/'+url
else:
#如果含有http说明是外链，url的host不是当前的host，返回空
return
else:
if not url.startswith('http'):
url='http://'+url
if is_next_url:
#下一层url放入待检测列表
if url not in CHECKING_URL:
CHECKING_URL.append(url)
else:
#对于当前需要检测的url将参数都替换为1，然后加入规则表
#参数相同类型不同的url只检测一次
rule=re.compile(r'=.*?\&|=.*?$')
result=re.sub(rule,'=1&',url)
if result in CHECKED_URL:
return '[!] Url has checked!'
else:
CHECKED_URL.append(result)
RESULT.append(url)
return url
def __is_connectable(self):
print("进入__is_connectable()函数")
#检验是否可以连接
retry=3
timeout=2
for i in range(RETRY):
try:
#print("进入_..............函数")
response=urllib2.urlopen(self.url,timeout=TIMEOUT)
return True
except:
if i==retry-1:
return False
def get_next(self):
#获取当前所有的url
#print("进入get_next()函数")
soup=BeautifulSoup(self.content)
next_urls=soup.findAll('a')
if len(next_urls)!=0:
for link in next_urls:
self.handle_url(link.get('href'))
#print(link.text)
def run(self):
#print("进入run()函数")
if self.url:
#print self.url
if self.__is_connectable():
try:
self.content=urllib2.urlopen(self.url,timeout=TIMEOUT).read()
self.get_next()
except:
print('[!]Connect Failed')
#处理https开头的url的类和方法
class Poc:
def run(self,url):
global HOST
global CHECKING_URL
url=check_url(url)
if not url.find('https'):
HOST=url[:8]
else:
HOST=url[7:]
for url in CHECKING_URL:
print(url)
url_node(url).run()
def check_url(url):
url='http://'+url if not url.startswith('http') else url
url=url[0:len(url)-1] if url.endswith('/') else url
for i in range(RETRY):
try:
response=urllib2.urlopen(url,timeout=TIMEOUT)
return url
except:
raise Exception("Connect error")
if __name__=='__main__':
HOST='www.dataanswer.com'
CHECKING_URL.append('http://www.dataanswer.com/')
f=open('36大数据','w')
for url in CHECKING_URL:
f.write(url+'\n')
print(url)
url_node(url).run()
print RESULT
print "URL num:"+str(len(RESULT))
print("time:%d s") % (time.time()-t) 八，多线程#!/usr/bin/env python
# -*- coding:utf-8 -*-
"""
一个简单的Python爬虫, 使用了多线程,
爬取豆瓣Top前250的所有电影
"""
import urllib2, re, string
import threading, Queue, time
import sys
reload(sys)
sys.setdefaultencoding('utf8')
_DATA = []
FILE_LOCK = threading.Lock()
SHARE_Q = Queue.Queue() #构造一个不限制大小的的队列
_WORKER_THREAD_NUM = 3 #设置线程的个数
class MyThread(threading.Thread) :
def __init__(self, func) :
super(MyThread, self).__init__() #调用父类的构造函数
self.func = func #传入线程函数逻辑
def run(self) :
self.func()
def worker() :
global SHARE_Q
while not SHARE_Q.empty():
url = SHARE_Q.get() #获得任务
my_page = get_page(url)
find_title(my_page) #获得当前页面的电影名
#write_into_file(temp_data)
time.sleep(1)
SHARE_Q.task_done()
def get_page(url) :
"""
根据所给的url爬取网页HTML
Args:
url: 表示当前要爬取页面的url
Returns:
返回抓取到整个页面的HTML(unicode编码)
Raises:
URLError:url引发的异常
"""
try :
my_page = urllib2.urlopen(url).read().decode("utf-8")
except urllib2.URLError, e :
if hasattr(e, "code"):
print "The server couldn't fulfill the request."
print "Error code: %s" % e.code
elif hasattr(e, "reason"):
print "We failed to reach a server. Please check your url and read the Reason"
print "Reason: %s" % e.reason
return my_page
def find_title(my_page) :
"""
通过返回的整个网页HTML, 正则匹配前100的电影名称
Args:
my_page: 传入页面的HTML文本用于正则匹配
"""
temp_data = []
movie_items = re.findall(r'<span.*?class="title">(.*?)</span>', my_page, re.S)
for index, item in enumerate(movie_items) :
if item.find(" ") == -1 :
#print item,
temp_data.append(item)
_DATA.append(temp_data)
def main() :
global SHARE_Q
threads = []
douban_url = "http://movie.douban.com/top250?start={page}&filter=&type="
#向队列中放入任务, 真正使用时, 应该设置为可持续的放入任务
for index in xrange(10) :
SHARE_Q.put(douban_url.format(page = index * 25))
for i in xrange(_WORKER_THREAD_NUM) :
thread = MyThread(worker)
thread.start() #线程开始处理任务
print("第%s个线程开始工作") % i
threads.append(thread)
for thread in threads :
thread.join()
SHARE_Q.join()
with open("movie.txt", "w+") as my_file :
for page in _DATA :
for movie_name in page:
my_file.write(movie_name + "\n")
print "Spider Successful!!!"
if __name__ == '__main__':
main()九,爬虫框架Scrapy在parse方法里面提取我们需要的链接，然后构造一些Request对象，并且把他们返回，scrapy会自动的去抓取这些链接
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原文地址：http://blog.csdn.net/javachaoco/article/details/51398075
