爬虫类型：通用爬虫、聚焦爬虫、增量式爬虫
在使用fiddler工具抓包时，需要注意下：因为它需要安装证书，在项目请求HTTPS页面是会ssl要求提供安全证书，可能会被拒绝请求
可以在发送requests请求时，关闭安全认证，或者暂时关闭fiddler代理。末尾也会提到，这个坑……
使用 BeautifulSoup对HTML标签进行解析数据：
import requests
from bs4 import BeautifulSoup
url='https://www.yangguiweihuo.com/16/16089/'
ua={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
page_text=requests.get(url=url,headers=ua).text #获取所有章节列表HTML
soup=BeautifulSoup(page_text,'lxml')
a_list=soup.select('.listmain > dl > dd > a') #解析出所有章节的URL
with open("秦吏.txt",'w',encoding='utf-8')as f:
for a in a_list:
title=a.string #获取a标签中的文本 作为章节名
detail_url='https://www.yangguiweihuo.com'+a['href'] #拼接章节详情url
detail_page=requests.get(url=detail_url,headers=ua).text
dsp=BeautifulSoup(detail_page,'lxml') #章节详情页面
content=dsp.find('div',id='content').text #章节内容详情
f.write(title+'
'+content) #数据持久化存储
print(title+"：下载完成")
print('The end')
f.close()
关于xpath的使用：
div[@class="song"] div中class为song的标签元素
div[@class="song"]/li/a/@href 取出其中的url地址
div[@class="song"]/li/a/text() 取出其中的文本
div[contains(@class,'ng')] 是指在div中查找class属性名含有ng的标签元素
div[starts-with(@class,'ta')] 是指div中查找class属性以ta开头的标签元素
xpath小案例：
import requests
from lxml import etree
url="https://gz.58.com/ershoufang/?PGTID=0d100000-0000-335c-5dda-1cebcdf9ae5f&ClickID=2"
user_agent={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
page_text=requests.get(url,headers=user_agent).text
tree=etree.HTML(page_text) #格式化处理后的全部页面数据
li_list=tree.xpath('//ul[@class="house-list-wrap"]/li') #记录以列表返回
fp=open("58.scv",'w',encoding='utf-8')
for li in li_list:
title=li.xpath("./div[@class='list-info']/h2/a/text()")[0]
price=li.xpath("./div[@class='price']//text()")
sum_price=''.join(price)
fp.write("home:"+title+"price:"+sum_price+'
')
fp.close()
print("数据获取完成！")
碰到网站文本乱码问题的解决：
import requests,os
from lxml import etree
url='http://pic.netbian.com/4kmeinv/'
user_agent={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
page_text=requests.get(url,headers=user_agent).text
tree=etree.HTML(page_text)
li_list=tree.xpath('//div[@class="slist"]/ul/li')
def getpic(title,photo):
if not os.path.exists('./photo'): #没有文件夹则直接创建空文件夹
os.mkdir('./photo')
fp = open('photo/'+title, 'wb')
fp.write(photo)
fp.close()
return "当前资源下载完成"
for li in li_list:
title=li.xpath('./a/b/text()')[0]+".jpg"
title=title.encode('iso-8859-1').decode('gbk') #乱码 转标准格式在解码
print(title)
p_url=li.xpath('./a/img/@src')[0]
picture_url='http://pic.netbian.com'+p_url
photo=requests.get(url=picture_url,headers=user_agent).content
ret=getpic(title,photo)
print(ret)
批量获取简历模板：字符乱码问题的处理
import requests,random,os,time
from lxml import etree
url='http://sc.chinaz.com/jianli/free.html'
user_agent={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
response=requests.get(url,headers=user_agent) #简历列表页面
response.encoding='utf-8' #对乱码进行处理
page_text=response.text
tree=etree.HTML(page_text)
div_list=tree.xpath('//div[@id="container"]/div')
if not os.path.exists('./jl'):
os.mkdir('./jl')
for div in div_list:
title=div.xpath('./a/img/@alt')[0] #简历名称
link=div.xpath('./a/@href')[0] #简历详情地址
fp=open('./jl/'+title+'.zip','wb')
detail_page=requests.get(url=link,headers=user_agent).text #简历详情页面
dpage=etree.HTML(detail_page)
down_list=dpage.xpath('//div[@class="clearfix mt20 downlist"]/ul/li/a/@href')
down_url=random.choice(down_list) #随机选择下载地址
word=requests.get(url=down_url,headers=user_agent).content
print("准备开始下载>>"+title)
fp.write(word)
time.sleep(1)
对代理ip进行测试：写入数据则代理ip可用
import requests
url='https://www.baidu.com/s?wd=ip'
user_agent={"User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36"}
proxy={"https":'112.85.170.79:9999'}
page=requests.get(url,headers=user_agent,proxies=proxy).text
with open('./ip.html','w',encoding='utf-8')as f:
f.write(page)
这一天天的mmp,当指定headers的User-Agent时,服务器会重定向到https的网址.因此报出SSL验证失败的错误，为了避免重定向造成认证失败，直接关闭认证page_text=requests.get(url=url,headers=user_agent,verify=False).text