一、为什么要搭建爬虫代理池

在众多的网站防爬措施中，有一种是根据ip的访问频率进行限制，即在某一时间段内，当某个ip的访问次数达到一定的阀值时，该ip就会被拉黑、在一段时间内禁止访问。

应对的方法有两种：

1. 降低爬虫的爬取频率，避免IP被限制访问，缺点显而易见：会大大降低爬取的效率。

2. 搭建一个IP代理池，使用不同的IP轮流进行爬取。

二、搭建思路

1、从代理网站(如：西刺代理、快代理、云代理、无忧代理)爬取代理IP；

2、验证代理IP的可用性（使用代理IP去请求指定URL，根据响应验证代理IP是否生效）；

3、将可用的代理IP保存到数据库；

常用代理网站：西刺代理、云代理、IP海、无忧代理、飞蚁代理、快代理

三、代码实现

工程结构如下：

ipproxy.py

IPProxy代理类定义了要爬取的IP代理的字段信息和一些基础方法。

# -*- coding: utf-8 -*-
import re
import time
from settings import PROXY_URL_FORMATTER

schema_pattern = re.compile(r'http|https$', re.I)
ip_pattern = re.compile(r'^([0-9]{1,3}.){3}[0-9]{1,3}$', re.I)
port_pattern = re.compile(r'^[0-9]{2,5}$', re.I)

class IPProxy:
    '''
    {
        "schema": "http", # 代理的类型
        "ip": "127.0.0.1", # 代理的IP地址
        "port": "8050", # 代理的端口号
        "used_total": 11, # 代理的使用次数
        "success_times": 5, # 代理请求成功的次数
        "continuous_failed": 3, # 使用代理发送请求，连续失败的次数
        "created_time": "2018-05-02" # 代理的爬取时间
    }
    '''

    def __init__(self, schema, ip, port, used_total=0, success_times=0, continuous_failed=0,
                 created_time=None):
        """Initialize the proxy instance"""
        if schema == "" or schema is None:
            schema = "http"
        self.schema = schema.lower()
        self.ip = ip
        self.port = port
        self.used_total = used_total
        self.success_times = success_times
        self.continuous_failed = continuous_failed
        if created_time is None:
            created_time = time.strftime('%Y-%m-%d', time.localtime(time.time()))
        self.created_time = created_time

    def _get_url(self):
        ''' Return the proxy url'''
        return PROXY_URL_FORMATTER % {'schema': self.schema, 'ip': self.ip, 'port': self.port}

    def _check_format(self):
        ''' Return True if the proxy fields are well-formed,otherwise return False'''
        if self.schema is not None and self.ip is not None and self.port is not None:
            if schema_pattern.match(self.schema) and ip_pattern.match(self.ip) and port_pattern.match(self.port):
                return True
        return False

    def _is_https(self):
        ''' Return True if the proxy is https,otherwise return False'''
        return self.schema == 'https'


if __name__ == '__main__':
    proxy = IPProxy('HTTPS', '1922.168.2.25', "8080")
    print(proxy._get_url())
    print(proxy._check_format())
    print(proxy._is_https())

settings.py

settings.py中汇聚了工程所需要的配置信息。

# 指定Redis的主机名和端口
REDIS_HOST = 'localhost'
REDIS_PORT = 6379

# 代理保存到Redis key 格式化字符串
PROXIES_REDIS_FORMATTER = 'proxies::{}'
# 已经存在的HTTP代理和HTTPS代理集合
PROXIES_REDIS_EXISTED = 'proxies::existed'

# 最多连续失败几次
MAX_CONTINUOUS_TIMES = 3
# 代理地址的格式化字符串
PROXY_URL_FORMATTER = '%(schema)s://%(ip)s:%(port)s'

USER_AGENT_LIST = [
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1",
    "Mozilla/5.0 (X11; CrOS i686 2268.111.0) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 Safari/536.11",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1092.0 Safari/536.6",
    "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.6 (KHTML, like Gecko) Chrome/20.0.1090.0 Safari/536.6",
    "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/19.77.34.5 Safari/537.1",
    "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.9 Safari/536.5",
    "Mozilla/5.0 (Windows NT 6.0) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.36 Safari/536.5",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
    "Mozilla/5.0 (Windows NT 5.1) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_0) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1063.0 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1062.0 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1062.0 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.1 Safari/536.3",
    "Mozilla/5.0 (Windows NT 6.2) AppleWebKit/536.3 (KHTML, like Gecko) Chrome/19.0.1061.0 Safari/536.3",
    "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/535.24 (KHTML, like Gecko) Chrome/19.0.1055.1 Safari/535.24",
    "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/535.24 (KHTML, like Gecko) Chrome/19.0.1055.1 Safari/535.24"
]
# 爬取到的代理保存前先检验是否可用，默认True
PROXY_CHECK_BEFOREADD = True
# 检验代理可用性的请求地址
PROXY_CHECK_URLS = {'https':['https://icanhazip.com'],'http':['http://icanhazip.com']}

Python爬虫代理池搭建

一、为什么要搭建爬虫代理池

二、搭建思路

三、代码实现

ipproxy.py

settings.py

猜你喜欢