Scrapy爬取西刺代理ip流程

西刺代理爬蟲

1. 新建項目和爬蟲

scrapy startproject daili_ips
......
cd daili_ips/
#爬蟲名稱和domains
scrapy genspider xici xicidaili.com

2. 測試

In [1]: import requests
In [2]: r = requests.get('http://www.xicidaili.com/nn/1')
In [3]: r.status_code
Out[3]: 500
In [4]: 

返回500, 猜測是沒有加User-Agent導致

In [4]: headers = {'User-Agent':'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36'}
In [5]: 
In [5]: r = requests.get('http://www.xicidaili.com/nn/1', headers=headers)
In [6]: r.status_code
Out[6]: 200
In [7]: 

返回正常

3. 在項目的settings中去掉USER_AGENT的注釋

# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36'

4. 編寫items.py

item定義存儲哪些字段

import scrapy


class DailiIpsItem(scrapy.Item):
    ip = scrapy.Field()
    port = scrapy.Field()
    position = scrapy.Field()
    type = scrapy.Field()
    speed = scrapy.Field()
    last_check_time = scrapy.Field()

5. 編寫spider

# -*- coding: utf-8 -*-
import scrapy
from daili_ips.items import DailiIpsItem


class XiciSpider(scrapy.Spider):
    name = "xici"
    allowed_domains = ["xicidaili.com"]
    start_urls = (
        'http://www.xicidaili.com/',
    )

    def start_requests(self):
        res = []
        for i in range(1, 2):
            url = 'http://www.xicidaili.com/nn/%d'%i
            req = scrapy.Request(url)
            # 存儲所有對應地址的請求
            res.append(req)
        return res

    def parse(self, response):
        table = response.xpath('//table[@id="ip_list"]')[0]
        trs = table.xpath('//tr')[1:]   #去掉標題行
        items = []
        for tr in trs:
            pre_item = DailiIpsItem()
            pre_item['ip'] = tr.xpath('td[2]/text()').extract()[0]
            pre_item['port'] = tr.xpath('td[3]/text()').extract()[0]
            pre_item['position'] = tr.xpath('string(td[4])').extract()[0].strip()
            pre_item['type'] = tr.xpath('td[6]/text()').extract()[0]
            pre_item['speed'] = tr.xpath('td[7]/div/@title').re('\d+\.\d*')[0]
            pre_item['last_check_time'] = tr.xpath('td[10]/text()').extract()[0]
            items.append(pre_item)
        return items

編寫spider的時候可以通過命令行工具scrapy shell url來測試要提取數據的xpath語法, 這樣更高效

6. 編寫Pipelines

# -*- coding: utf-8 -*-

# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: http://doc.scrapy.org/en/latest/top ics/item-pipeline.html
import MySQLdb

class DailiIpsPipeline(object):
    # 該函數必須返回一個具有數據的dict或者item對象
    def process_item(self, item, spider):
        DBS = spider.settings.get('DBS')
        con = MySQLdb.connect(**DBS)
        # 下面這行代碼表示設置MySQL使用的字符集為utf8
        con.set_character_set('utf8')
        cur = con.cursor()
        insert_sql = (
            "insert into proxy (ip, port, position, type, speed, last_check_time) "
            "values (%s,%s,%s,%s,%s,%s);"
        )
        values = (item['ip'], item['port'], item['position'], item['type'], item['speed'], item['last_check_time'])
        # 插入數據庫
        try:
            cur.execute(insert_sql, values)
        except Exception, e:
            print "插入失敗: ", e
            con.rollback()
        else:
            con.commit()
        cur.close()
        con.close()
        return item




        return item

注意:
這里我剛開始做的時候沒有加con.set_character_set('utf8')這一行, 結果報錯如下

UnicodeEncodeError: 'latin-1' codec can't encode character

但是我在創建數據表的時候已經設置字符集為utf8, 查資料后是MySQLdb正常情況下會嘗試將所有的內容轉為latin1字符集處理
所以處理方法就是，設置連接和游標的charset為你所希望的編碼

con = MySQLdb.connect(...)
# 設置鏈接編碼
con.set_character_set('utf8')
cur = con.cursor()
# 設置游標編碼
cur.execute('SET NAMES utf8;')
cur.execute('SET CHARACTER SET utf8;')
cur.execute('SET CHARACTER_SET_CONNECTION=utf8;')

我在測試后發現僅僅設置連接(con)的編碼也不會報錯, 所以上述程序並沒有設置游標編碼

7. 創建MySQL數據表

mysql> create table porxy(
    -> id int primary key auto_increment,
    -> ip varchar(20),
    -> port varchar(20),
    -> position varchar(20),
    -> type varchar(20),
    -> speed varchar(20),
    -> last_check_time varchar(20)
    -> )charset=utf8;
Query OK, 0 rows affected (0.01 sec)

mysql> 

8. 啟用Pipelines

更改settings.py文件, 取消注釋

# Configure item pipelines
# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
#    'daili_ips.pipelines.SomePipeline': 300,
#}

改為

ITEM_PIPELINES = {
   'daili_ips.pipelines.DailiIpsPipeline': 300,
}

后面的數字一般在0-1000以內, 當有多個Pipelines的時候表示執行順粗, 數字小的先執行

啟動爬蟲

scrapy crawl xici