Python爬虫学习笔记(二)

发表于:2021-06-17 16:36 阅读: 120次

这篇教程主要讲解了Python爬虫学习笔记(二),并附有相关的代码样列,我觉得非常有帮助,现在分享出来大家一起学习!

GET + 字典传参:

代码:

import urllib.request
import urllib.parse
import string


def get_params():
    url = "http://www.baidu.com/s?wd="

    params = {
        "wd": "中文",
        "key": "zhang",
        "value": "san",

    }
    str_params = urllib.parse.urlencode(params)
    print(str_params)
    final_url = url + str_params

    #讲带有中文的url转义成计算机可以识别的URL
    end_url = urllib.parse.quote(final_url, safe=string.printable)

    response = urllib.request.urlopen(end_url)
    data = response.read().decode("utf-8")
    print(data)


get_params()
GET + params + 字典

返回结果:

 

GET传参:

(1)汉字报错:

解释器ascii没有汉字,url汉字转码

urllib.parse.quote(params, safe=string.printable)

(2)字典传参:

urllib.parse.urlencode()

注:

POST请求:

urllib.request.urlopen(url, data="服务器接收的数据")

 

hander:

User-Agent:

(1)模拟真实的浏览器发送请求:百度批量搜索,检察元素

(2)request.add_header()动态添加head数据

(3)响应头:response.header

(4)创建request:urllib.request.Request(url)

Test(响应头):

代码:

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"
    response = urllib.request.urlopen(url)
    print(response)

    #响应头
    print(response.headers)


load_baidu()
响应头

返回:

E:\python\python.exe H:/code/Python爬虫/Day02/02-request_header.py
<http.client.HTTPResponse object at 0x000001F64CC88CA0>
Bdpagetype: 1
Bdqid: 0x9829fa7c000a56cf
Cache-Control: private
Content-Type: text/html;charset=utf-8
Date: Tue, 26 Jan 2021 06:35:11 GMT
Expires: Tue, 26 Jan 2021 06:34:11 GMT
P3p: CP=" OTI DSP COR IVA OUR IND COM "
P3p: CP=" OTI DSP COR IVA OUR IND COM "
Server: BWS/1.1
Set-Cookie: BAIDUID=A276C955F91E3B32F4D56ADC1EE37C59:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BIDUPSID=A276C955F91E3B32F4D56ADC1EE37C59; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: PSTM=1611642911; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BAIDUID=A276C955F91E3B3283913B84A5B12CFA:FG=1; max-age=31536000; expires=Wed, 26-Jan-22 06:35:11 GMT; domain=.baidu.com; path=/; version=1; comment=bd
Set-Cookie: BDSVRTM=0; path=/
Set-Cookie: BD_HOME=1; path=/
Set-Cookie: H_PS_PSSID=33425_33507_33437_33257_33273_31253_33395_33398_33321_33265; path=/; domain=.baidu.com
Traceid: 1611642911060665933810964570178293749455
Vary: Accept-Encoding
Vary: Accept-Encoding
X-Ua-Compatible: IE=Edge,chrome=1
Connection: close
Transfer-Encoding: chunked



Process finished with exit code 0
View Code

Test(获取请求头信息):

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"

    #创建请求对象
    request = urllib.request.Request(url)
    #请求网络数据
    response = urllib.request.urlopen(request)
    #print(response)
    data = response.read().decode("utf-8")
    #响应头
    #print(response.headers)

    #获取请求头的信息
    request_header = request.headers
    print(request_header)
    with open("02header.html", "w")as f:
        f.write(data)


load_baidu()
获取请求头的信息

Test(添加请求头信息):

代码1:

法一:自行获取

返回1:

E:\python\python.exe H:/code/Python爬虫/Day02/03-request_header_two.py
{'User-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36', '3ch0 - nu1l': 's1mpL3'}

Process finished with exit code 0
View Code

代码2:

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"
    header = {
        #浏览器版本
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36",
        "3cH0 - Nu1L": "s1mpL3",

    }
    #创建请求对象
    request = urllib.request.Request(url, headers=header)
    #请求网络数据(不在此处增加请求头信息,因为此方法系统没有提供参数)
    response = urllib.request.urlopen(request)
    data = response.read().decode("utf-8")

    #获取请求头的信息(所有头的信息)
    #request_headers = request.headers
    #print(request_headers)
    #第二种方式打印headers信息
    request_headers = request.get_header("User-agent")
    print(request_headers)
    with open("02header.html", "w")as f:
        f.write(data)


load_baidu()
法二:内置函数获取

返回2:

E:\python\python.exe H:/code/Python爬虫/Day02/03-request_header_two.py
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36

Process finished with exit code 0
View Code

注1:

对比两次返回值:

使用内置函数时,不返回字典中的"3cH0 - Nu1L": "s1mpL3",

自行获取时则都返回

注2:

中首字母要大写(其余均小写),若改为小写,则返回值为None

代码:

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"
    header = {
        #浏览器版本
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36",
        "3cH0 - Nu1L": "s1mpL3",

    }
    #创建请求对象
    request = urllib.request.Request(url, headers=header)
    #请求网络数据(不在此处增加请求头信息,因为此方法系统没有提供参数)
    response = urllib.request.urlopen(request)
    data = response.read().decode("utf-8")

    #获取请求头的信息(所有头的信息)
    #request_headers = request.headers
    #print(request_headers)
    #第二种方式打印headers信息
    request_headers = request.get_header("user-agent")
    print(request_headers)
    with open("02header.html", "w")as f:
        f.write(data)


load_baidu()
View Code

返回:

E:\python\python.exe H:/code/Python爬虫/Day02/03-request_header_two.py
None

Process finished with exit code 0
View Code

Test(动态添加Header信息):

代码:

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"
    header = {
        # 浏览器版本
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36",
        "3cH0 - Nu1L": "s1mpL3",

    }
    #创建请求对象
    request = urllib.request.Request(url)
    #动态添加hander信息
    request.add_header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36")
    #请求网络数据
    response = urllib.request.urlopen(request)
    #print(response)
    data = response.read().decode("utf-8")
    #响应头
    #print(response.headers)

    #获取请求头的信息
    request_header = request.headers
    print(request_header)
    with open("02header.html", "w")as f:
        f.write(data)


load_baidu()
View Code

返回:

E:\python\python.exe H:/code/Python爬虫/Day02/03-request_header_two.py
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36

Process finished with exit code 0
View Code

Test(获取完整的url):

代码:

import urllib.request

def load_baidu():
    url = "http://www.baidu.com/"
    header = {
        # 浏览器版本
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36",
        "3cH0 - Nu1L": "s1mpL3",

    }
    #创建请求对象
    request = urllib.request.Request(url)
    #动态添加hander信息
    request.add_header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36")
    #请求网络数据
    response = urllib.request.urlopen(request)
    #print(response)
    data = response.read().decode("utf-8")
    #获取完整的url
    final_url = request.get_full_url()
    print(final_url)


load_baidu()
View Code

返回:

Test(随机user-agent):

需要多份user-agent(网上搜索user-agent大全即可)

代码:

import urllib.request
import random

def load_baidu():
    url = "http://www.baidu.com"
    user_agent_list = [
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1",
        "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.50 (KHTML, like Gecko) Version/5.1 Safari/534.50",
        "Opera/9.80 (Windows NT 6.1; U; zh-cn) Presto/2.9.168 Version/11.50",

    ]
    #每次请求的浏览器都是不一样的
    random_user_agent = random.choice(user_agent_list)

    request = urllib.request.Request(url)

    #增加对应的响应头(user-agent)
    request.add_header("User-Agent", random_user_agent)

    #请求数据
    response = urllib.request.urlopen(request)
    #获取请求头的信息
    print(request.get_header("User-agent"))


load_baidu()
View Code

返回:

具有随机性

 

IP代理:

(1)免费IP:时效性差,错误率高

(2)付费IP:也存在失效的

IP分类:

透明IP:

对方知道我们的真实IP

匿名IP:

对方不知道我们的真实IP,知道我们使用了代理

高匿IP:

既不知道真实IP,也不知道使用了代理

handler:

系统的urlopen()不支持代理的添加

创建对应的处理器(handler)

  1. 代理处理器:ProxyHandler
  2. 用ProxyHandler创建openner:build_openner()
  3. openner.open(url)就可以请求数据

Test(HTTPHandler):

代码:

import urllib.request

def handler_openner():

    #系统的urlopen没有添加代理的功能,需要我们自定义该功能
    #安全 套接层 ssl第三方的CA数字证书
    #http:80
    #https:443
    #urlopen为什么可以请求数据:
    #①handler处理器,
    #②自己的openner请求数据
    url = "https://www.cnblogs.com/3cH0-Nu1L/"

    #创建自己的处理器
    handler = urllib.request.HTTPHandler
    #创建自己的oppener
    openner = urllib.request.build_opener(handler)
    #用自己创建的openner调用open方法请求数据
    response = openner.open(url)
    data = response.read()
    print(response)
    print(data)


handler_openner()
handler_openner

返回:

注:

HTTPHandler()不可以增加代理

Test(使用代理IP_免费IP):

代码:

import urllib.request

def create_proxy_handler():
    url = "https://www.cnblogs.com/3cH0-Nu1L/"

    #添加代理
    proxy = {
        #免费的写法
        "http": "104.131.109.66:8080"

    }
    #代理处理器
    proxy_handler = urllib.request.ProxyHandler(proxy)

    #创建自己的openner
    openner = urllib.request.build_opener(proxy_handler)
    #拿着代理IP发送请求
    data = openner.open(url).read()
    print(data)


create_proxy_handler()
Proxy_handler

返回:

Test(随机创建):

代码:

import urllib.request

def proxy_user():

    proxy_list = [
        {"http": "104.131.109.66:8080"},
        {"http": "88.198.24.108:8080"},
        {"http": "96.113.165.182:3128"},
        {"http": "117.185.17.151:80"},
        {"http": "112.30.164.18:80"},

    ]
    for proxy in proxy_list:
        print(proxy)
        #利用遍历出来的IP创建处理器
        proxy_handler = urllib.request.ProxyHandler(proxy)
        #创建openner
        openner = urllib.request.build_opener(proxy_handler)

        try:
            openner.open("http://www.baidu.com", timeout=1)
            print("s1mpL3")
        except Exception as e:
            print(e)


proxy_user()
View Code

返回:

E:\python\python.exe H:/code/Python爬虫/Day02/07-random-user-proxy.py
{'http': '104.131.109.66:8080'}
s1mpL3
{'http': '88.198.24.108:8080'}
<urlopen error timed out>
{'http': '96.113.165.182:3128'}
s1mpL3
{'http': '117.185.17.151:80'}
s1mpL3
{'http': '112.30.164.18:80'}
<urlopen error timed out>

Process finished with exit code 0
View Code

Test(使用代理IP_付费IP):

代码:

import urllib.request
import requests

#付费代理发送
#1.用户名密码(带着)
#通过验证的处理起来发送

def money_proxy_user():
    #1.代理IP
    money_proxy = {
        "http": "username:passwd@192.168.12.1:8080"
    }
    #2.代理的处理器
    proxy_handler = urllib.request.ProxyHandler(money_proxy)
    #3.通过处理器创建openner
    openner = urllib.request.build_opener(proxy_handler)
    #4.open发送请求
    openner.open("http://www.baidu.com/")


money_proxy_user()
方式一
import urllib.request
import requests

#付费代理发送
#1.用户名密码(带着)
#通过验证的处理起来发送

def money_proxy_user():
    # 第二种方式发送付费的IP地址
    user_name = "abcname"
    passwd = "123456"
    proxy_money = "123.158.62.120:8080"
    # 2.创建密码管理器,添加用户名和密码
    password_manager = urllib.request.HTTPPasswordMgrWithDefaultRealm()
        #uri定位 uri > url
        #url:资源定位符
    password_manager.add_password(None, proxy_money, user_name, passwd)
    # 3.创建可以验证代理IP的处理器
    handler_auth_proxy = urllib.request.ProxyBasicAuthHandler(password_manager)
    # 4.根据处理器创建openner
    openner_auth = urllib.request.build_opener(handler_auth_proxy)
    # 5.发送请求
    response = openner_auth.open("http:www.baidu.com")
    print(response.read())


money_proxy_user()
方式二

 

Auth认证:

爬取自己网站的数据进行分析,类似使用付费代理IP的过程。

Test:

代码:

import urllib.request

def auth_neiwang():
    # 1.用户名密码
    user = "admin"
    password ="admin123"
    nei_url = "http://192.168.179.66"

    # 2.创建密码管理器
    pwd_manager = urllib.request.HTTPPasswordMgrWithDefaultRealm()
    pwd_manager.add_password(None, nei_url, user, password)

    # 3.创建认证处理器(requests)
    auth_handler = urllib.request.HTTPBasicAuthHandler(pwd_manager)
    openner = urllib.request.build_opener(auth_handler)
    response = openner.open(nei_url)
    print(response)


auth_neiwang()
View Code

以上就是Python爬虫学习笔记(二)的全部内容,希望对大家的学习有所帮助,如果觉得有用给我点个赞吧,同时也希望大家多多支持酷码派。

酷码派 [KuMaPai.COM] - 陕ICP备18010024号-2