python爬虫备忘录

我都不知道多久没有发过博文了，伴随着毕业的到来，论文和实习，都一起到来了，可能我以后也很少发布编程类的文章了，更多的将会注重于网络安全文章的发布了，windowsAPI的文章将会逐渐从我的博文中删除，以后将会不定期更新webdirscan，weblogon_brust等的python技术文章，二进制或者手机APP类型的，很感叹自己一路走过来，学习了不少的知识，也遇到过很多大佬，向他们学习了一些知识，到如今，我还是觉得脚踏实地的走比较靠谱。之后我会陆续更新我的开源webdirscan软件，开源一些信息收集的小工具。

爬虫环境配置

selenium

描述：模拟浏览器访问，有界面
安装: pip3 install selenium
基本使用:
import selenium
from selenium import webdriver
driver=webdriver.Chrome()

chromedriver

描述：谷歌驱动
安装：pip install chromedriver
基本使用:
import selenium
from selenium import webdriver
driver=webdriver.Chrome()

phantomjs

描述：模拟浏览器访问，无界面
安装: 下载https://phantomjs.org/download
配置：
export PATH=${PATH}:/root/phantomjs/bin
export OPENSSL_CONF=/etc/ssl/

beautifulsoup4

描述：html
安装: pip3 install beautifulsoup4
使用:
from bs4 import BeautifulSoup
soup=BeautifulSoup('<html><html>','lxml')

pyquery

描述：类似Jquery
安装: pip3 install pyquery
使用:
from pyquery import PyQuery as pq
doc=pq('<html>HELLO</html>')
result=doc('html').text()
result

pymysql

描述：mysql
安装: pip3 install pymysql
使用：
import pymysql
conn=pymysql.connect(host='127.0.0.1',user='root',password='root',port=3306,db='mysql')
cursor=conn.cursor()
cursor.execute('select * from db')
cursor.fetchone()
出错解决:
update mysql.user set authentication_string=PASSWORD('root'), plugin='mysql_native_password' where user='root';

pymongo

描述：MongoDB
安装：pip3 install pymongo
使用:
import pymongo
client=pymongo.MongoClient('localhost')
db=client['newtestdb']
db['table'].insert({'name':'Bob'})
db['table'].find_one({name':'Bob'})

pyredis

描述：Redis
安装：pip3 install redis
使用:
import redis
r=redis.Redis('localhost',6379)
r.set('name','Bob')
r.get('name')

flask代理

描述：proxy
安装：pip3 install flask
使用：
import flask

django

描述：django
安装：pip3 install django
使用:
import django

jupyter

描述：makedown在线，编译在线
安装：pip3 install jupyter
使用:
jupyter notebook

ALL

pip3 install requests selenium beautifulsoup4 pyquery pymysql pymongo redis flask django jupyter

什么是爬虫？

一个简单的请求

import requests
response=request.get('https://www.baidu.com')
#response.decoding="utf8"
print(response.text)
print(response.header)
print(response.status_code)

headers={'User-Agent':"**********"}
response=requests.get('https://www.baidu.com',headers=headers)
print(response.status_code)

# 下载图片
response=request.get('https://www.baidu.com/gif.ico')
print(response.content)
with open('/var/tmp/1.git','wb') as f:
	f.write(response.content)
	f.close

JS(javascript)渲染问题

selenium/webDriver or Splash or pyv8、Ghost.py

from selenium import webdriver
driver=webdriver.Chrome()
driver.get('http://m.weibo.com')
print(driver.page_sources)

Urllib库

什么是Urllib?

内置请求：
urllib.request 请求模块
usllib.error 异常
urllib.parse url解析模块
urllib.robotparser robot.txt解析模块

相比python2变化:
python2:
impoort urllib2
response=usllib.urlopen('https://www.baidu.com')

python3:
import urllib.request
response=urllib.request.urlopen('https://www.baidu.com')

Requests库

import requests

response=requests.get('https://www.baidu.com')
print(type(response))
print(response.status_code)
print(type(response.text))
print(response.text)
print(response.cookies)

import requests
response=requests.get('http://www.baidu.com?id=1')
print(response.text)

参数:
import requests
data={
'name':'germay',
'age':22
}
response=requests.get('url',params=data)
print(response.text)

JSON:
import request
response=requests.get('url')
print(type(response.text))
print(response.json())
print(json.loads(response.text))
print(type(response.json()))

二进制:
import requests
response=request.get('url/img.ico')
print(response.text)
print(response.content)

with open('a.ico','web') as f:
	f.write(response.content)
	f.close()

headers:
import requests 
headers={
'User-Agent':'Moziila/5.0'
}
response =request.get('URL/explore',headers=headers)
print(response.text)

POST请求:
import request

data={'name':'asd','age':22}
response=request.post('http://www',data=data)
print(response.text)

import request

data={'name':'asd','age':22}
headers={
'User-Agent':'asdasdasd'
}
response=requests.post('URL',data=data,headers=headers)
print(response.json())

响应:
import requests

response=requests.get('URL')
print(response.status_code)
print(response.headers)
print(response.cookies)
print(response.url)
print(response.history)

状态码判断
import requests
response=request.get('URL')
exit() if not response.status_code==request.codes.ok else print('ok')
#exit() if not response.status_code==request.codes.200 else print('ok')

高级操作

文件上传:
import requests

files={'file',open('img.jpg','rb')}
response=requests.post('URL',file=files)
print(response.text)

获取cookie
import requests

response=request.get('URL')
print(response.cookies)
for key,value in reqonse.cookies.items():
	print(key+'='+value)

会话维持:
import requests
s=request.Session()
s.get('set cookie URL')
response=s.get('get cookie url')
print(response.text)

证书验证
import requests 
response=requests.get('URL')
print(response.status_code)

import requests 
from request.packages import urllib3
urllib3.disable_warinings()
response=requests.get('URL',verify=False)# 不认证证书
print(response.status_code)

import requests 
response=requests.get('URL',cert=('/path/server.crt','path/key'))
print(response.status_code)

代理设置:
import request

proxies={
'http':'http://127.0.0.1:1080',
'https':'https://127.0.0.1:1080'
}

response=request.get('URL',proxies=proxies)
print(response.status_code)


安装：pip install 'requests[socks]'
import requests

proxies={
'http':'socks5://127.0.0.1:1080',
'https':'socks5://127.0.0.1:1080'
}
response=request.get('URL',proxies=proxies)
print(response.status_code)

超时设置:
import requests
response=request.get('https://www.baidu.com',timeout=1)

认证设置(网站访问认证):
import requests
from requests.auth import HTTPBasicAuth
r=requests.get('http://127.0.0.1:9090',auth=HTTPBasicAuth('user',123))
print(r.status_code)

import requests
r=requests.get('http://127.0.0.1:9090',auth=('user','123'))
print(r.status_code)

异常处理：
import requests
from request.excception import ReadTimeout,HTTPError,RequestException

try:
	response=request.get('URL',timeout=1)
	print(response.status_code)
except ReadTimeout:
	print('...')
except HTTPError:
	print('...')
except RequestException:
	print('...')

re正则表达式

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match

re.match
从字符串起始位置匹配一个模式，没有就是None
re.match(pattern,staring,flags=0)

普通匹配:
impoer re
content="Hello 123 4567 World_This is a Regex Demo"
result=re.match('^Hellosdddsd[4]sw[10]ss[2].*Demo$',content)
print(result.group())
print(result.span())

泛匹配:
impoer re
content="Hello 123 4567 Wordld_This is a Regex Demo"
result=re.match("^Hello.*Demo$",content)
print(result.group())
print(result.span())

目标匹配:
impoer re
content="Hello 123 4567 Wordld_This is a Regex Demo"
result=re.match('^Hellos(d+)sWorld.*Demo$',content)# (d+)
print(result.group(1))
print(result.span())

贪婪匹配:
impoer re
content="Hello 123 4567 Wordld_This is a Regex Demo"
result=re.match("^He.*(d+).*Demo$",content)
print(result)
print(result.group(1))
print(result.span())

非贪婪匹配:
impoer re
content="Hello 123 4567 Wordld_This is a Regex Demo"
result=re.match("^He.*?(d+).*Demo$",content)
print(result)
print(result.group(1))

模式匹配:
impoer re
content="Hello 123 4567 Wordld_This
is a Regex Demo
"
result=re.match("^He.*?(d+).*?Demo$",content,re.S)#re.S 这样.*可以匹配任意字符
print(result)
print(result.group(1))

转义：
import re
content='price is $5.00'
result=re.match('price is $5.00',content)
print(result)
print(result.group(1))

search(一个)

re.search:
import re
content='Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
result=re.search('Hello.*?(d+).*?Demo',content)
print(result)
print(result.group(1))

findall(所有)

result=re.findall('<li.*?href="(.*?)".*?singer="(.*?)">(.*?)</a>',html.re.S)
print(result)

Sub

替换字符串中每一个匹配的字串后返回替换后的字符串
import re
content='Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
content=re.sub('d+','',content)
print(content)

import re
content='Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
content=re.sub('d+','replace',content)
print(content)

替换整体
import re
content='Extra strings Hello 1234567 World_This is a Regex Demo Extra strings'
content=re.sub('(d+)','r1 8910',content)
print(content)

compile

将一个正则表达式编译成表达式对象
import re
content='Extra strings Hello 1234567 World_This 
is a Regex Demo Extra strings'
pattern=re.compile("Hello.*Demo",re.S)
result=re.match(pattern,content)
print(result)
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原文地址：https://www.cnblogs.com/angels-yaoyao/p/12443595.html