怎样使用python爬虫获得免费代理ip

爬虫一直是python使用的一个重要部分，而许多网站也为此做了许多反爬措施，其中爬虫访问过于频繁直接封ip地址也作为一种“伤敌一千，自损八百”的方法被许多网站采用，代理ip便可以防止这种情况出现。

进行爬取和测试有效性

分析完毕开始爬取ip，直接使用第三方的requests和BeautifulSoup4，可以让抓取变得很方便，代码如下：

from iptools import header, dict2proxy
from bs4 import BeautifulSoup as Soup

def parse_items(items):
    # 存放ip信息字典的列表
    ips = []
    for item in items:
        tds = item.find_all('td')
        # 从对应位置获取ip，端口，类型
        ip, port, _type = tds[1].text, int(tds[2].text), tds[5].text
        ips.append({'ip': ip, 'port': port, 'type': _type})
    return ips

def check_ip(ip):
    try:
        proxy = dict2proxy(ip)
        url = 'https://www.ipip.net/'
        r = requests.get(url, headers=head, proxies=pro,timeout=5)
        r.raise_for_status()
    except:
        return False
    else:
        return True

def get_proxies(index):
    url = 'http://zhimaruanjian.com// % index
    r = requests.get(url, headers=header)
    r.encoding = r.apparent_encoding
    r.raise_for_status()
    soup = Soup(r.text, 'lxml')
    # 第一个是显示最上方的信息的，需要丢掉
    items = soup.find_all('tr')[1:]
    ips = parse_items(items)
    good_proxies = []
    for ip in ips:
        if check(ip):
            good_proxies.append(ip)
    return good_proxies

就像在上面写的，有效性我直接使用了ip查询网站，获得的ip基本确保可以直接使用。

写入json文件

可以将获取的ip存放在json文件中，json模块的使用也很简单，直接打开一个文件，使用dump方法写入文件即可，

import json

def write_to_json(ips):
    with open('proxies.json', 'w', encoding='utf-8') as f:
        json.dump(ips, f, indent=4)

写入MongoDB

写入数据库后获取和操作会很方便，

from pymongo import MongoClient as Client

def write_to_mongo(ips):
    client = Client(host='localhost', port=27017)
    db = client['proxies_db']
    coll = db['proxies']
    for ip in ips:
        if coll.find({'ip': ip['ip']}).count() == 0:
            coll.insert_one(ip)
    client.close()

写入后使用RoboMongo查看

使用多线程

导入threading包，将Thread封装一下，得到最终的代码

get_proxies.py
import json

import requests
import time

from proxies_get.iptools import header, dict2proxy
from bs4 import BeautifulSoup as Soup
from pymongo import MongoClient as Client
import threading


def parse_items(items):
    # 存放ip信息字典的列表
    ips = []
    for item in items:
        tds = item.find_all('td')
        # 从对应位置获取ip，端口，类型
        ip, port, _type = tds[1].text, int(tds[2].text), tds[5].text.lower()
        ips.append({'ip': ip, 'port': port, 'type': _type})

    return ips


def check_ip(ip, good_proxies):
    try:
        pro = dict2proxy(ip)
        # print(pro)
        url = 'https://www.ipip.net/'
        r = requests.get(url, headers=header, proxies=pro, timeout=5)
        r.raise_for_status()
        print(r.status_code, ip['ip'])
    except Exception as e:
        # print(e)
        pass
    else:
        good_proxies.append(ip)


def write_to_json(ips):
    with open('proxies.json', 'w', encoding='utf-8') as f:
        json.dump(ips, f, indent=4)


def write_to_mongo(ips):
    '''将数据写入mongoDB'''
    client = Client(host='localhost', port=27017)
    db = client['proxies_db']
    coll = db['proxies']
    # 先检测，再写入，防止重复
    for ip in ips:
        if coll.find({'ip': ip['ip']}).count() == 0:
            coll.insert_one(ip)
    client.close()


class GetThread(threading.Thread):
    '''对Thread进行封装'''
    def __init__(self, args):
        threading.Thread.__init__(self, args=args)
        self.good_proxies = []

    def run(self):
        url = 'http://zhimaruanjian.com/ % self._args[0]
        # 发起网络访问
        r = requests.get(url, headers=header)
        r.encoding = r.apparent_encoding
        r.raise_for_status()
        soup = Soup(r.text, 'lxml')
        # 第一个是显示最上方的信息的，需要丢掉
        items = soup.find_all('tr')[1:]
        ips = parse_items(items)
        threads = []
        for ip in ips:
            # 开启多线程
            t = threading.Thread(target=check_ip, args=[ip, self.good_proxies])
            t.start()
            time.sleep(0.1)
            threads.append(t)
        [t.join() for t in threads]

    def get_result(self):
        return self.good_proxies


if __name__ == '__main__':
    # 主函数使用多线程
    threads = []
    for i in range(1, 30):
        t = GetThread(args=[i])
        t.start()
        time.sleep(10)
        threads.append(t)
    [t.join() for t in threads]
    for t in threads:
        proxies = t.get_result()
        write_to_mongo(proxies)


iptools.py
header = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) '
                        'AppleWebKit/537.36 (KHTML, like Gecko) '
                        'Chrome/64.0.3282.186 Safari/537.36'}


def dict2proxy(dic):
    s = dic['type'] + '://' + dic['ip'] + ':' + str(dic['port'])
    return {'http': s, 'https': s}

总结

这个免费代理ip的爬虫没什么太难的地方，就是服务器有点弱，一不小心就503了，需要限制一下访问速度。使用免费的代理会影响使用到的效果，因此可以使用代理商代理ip服务，会更加的稳定安全。