scrapy框架提升篇
關注公衆號“輕鬆學編程”瞭解更多
1、創建啓動爬蟲腳本
在項目目錄下創建start.py文件:
添加代碼:
#以後只要運行start.py就可以啓動爬蟲
import scrapy.cmdline
def main():
#mytencent爲當前項目爬蟲名
scrapy.cmdline.execute(['scrapy', 'crawl', 'mytencent'])
if __name__ == '__main__':
main()
2、自動爬取多頁
在spiders文件夾下的mytencent.py中MytencentSpider類要繼承CrawlSpider,然後添加規則即可:
import scrapy
from tencent.items import TencentItem
from scrapy.spiders import CrawlSpider, Rule # 爬取規則
from scrapy.linkextractors import LinkExtractor # 提取鏈接
#爬蟲類繼承CrawlSpider
class MytencentSpider(CrawlSpider):
name = 'mytencent'
allowed_domains = ['hr.tencent.com']
start_urls = ['https://hr.tencent.com/position.php?keywords=&tid=0&start=10#a']
#添加爬取url規則,url符合正則start=(\d+)#a")就爬取
rules = (Rule(LinkExtractor(allow=("start=(\d+)#a")), callback='get_parse', follow=True),)
# 一定不能用parse()
def get_parse(self, response):
jobList = response.xpath('//tr[@class="even"] | //tr[@class="odd"]')
# 存儲對象
item = TencentItem()
for job in jobList:
# .extract()提取文本
jobName = job.xpath('./td[1]/a/text()').extract()[0]
jobType = job.xpath('./td[2]/text()').extract()[0]
item['jobName'] = jobName
item['jobType'] = jobType
yield item
3、使用框架自帶的Request()構建請求
在spiders文件夾下的mysina.py中:
import scrapy
from scrapy.spiders import CrawlSpider,Rule #爬取規則
from scrapy.linkextractor import LinkExtractor #提取鏈接
class MysinaSpider(CrawlSpider):
name = 'mysina'
allowed_domains = ['sina.com.cn']
start_urls = ['http://roll.news.sina.com.cn/news/gnxw/gdxw1/index_1.shtml']
#設置爬取規則,可迭代對象,可設置多個規則
rules = [Rule(LinkExtractor(allow=("index_(\d+).shtml")),callback='get_parse',follow=True)]
def get_parse(self, response):
newsList = response.xpath('//ul[@class="list_009"]/li')
for news in newsList:
# 新聞標題
title = news.xpath('./a/text()').extract()[0]
# 新聞時間
newsTime = news.xpath('./span/text()').extract()[0]
# print('***********',title,'****',newsTime)
#獲取正文的url
contentsUrl = news.xpath('./a/@href').extract()[0]
#使用框架自帶的Request()構建請求,使用meta傳遞參數
'''
scrapy.Request()參數列表:
url,
callback=None, 回調函數
meta=None, 數據傳遞
'''
request = scrapy.Request(url=contentsUrl,callback=self.get_article,)
# 使用meta傳遞參數 是一個字典, 只能傳遞一層
request.meta['title'] = title
request.meta['newsTime'] = newsTime
yield request
def get_article(self,response):
contents = response.xpath('//div[@id="article"]//text()')
#新聞內容
newsContent = ""
for content in contents:
newsContent += content.extract().strip()+'\n'
print('*****新聞正文*****',newsContent,'*****新聞正文*****')
item = SinaItem()
# 從meta中獲取參數
item['title'] = response.meta['title']
item['newsTime'] = response.meta['newsTime']
item['newsContent'] = newsContent
yield item
4、保存進MySQL數據庫模板
在MySQL中建立數據庫,表,然後在pipelines.py中編寫代碼如下:
import pymysql
class TencentPipeline(object):
def __init__(self):
#連接數據庫
self.conn = None
#遊標
self.cur = None
# 打開爬蟲時調用,只調用一次
def open_spider(self,spider):
self.conn = pymysql.connect(host='127.0.0.1',
user='root',
password="123456",
database='tjob', #數據庫爲tjob
port=3306,
charset='utf8')
self.cur = self.conn.cursor()
def process_item(self, item, spider):
clos,value = zip(*item.items())
sql = "INSERT INTO `%s`(%s) VALUES (%s)" % ('tencentjob', #表名爲tencentjob
','.join(clos),
','.join(['%s'] * len(value)))
self.cur.execute(sql, value)
self.conn.commit()
return item
def close_spider(self, spider):
self.cur.close()
self.conn.close()
settings.py中要開啓
ITEM_PIPELINES = {
'tencent.pipelines.TencentPipeline': 300,
}
5、使用中間件做UA代理,IP代理
在middlewares.py中添加:
from scrapy import signals
import random
#ip代理
from scrapy.downloadermiddlewares.httpproxy import HttpProxyMiddleware
#UA代理
from scrapy.downloadermiddlewares.useragent import UserAgentMiddleware
from weixinsougou.settings import USER_AGENTS,PROXIES
class RandomUAMiddleware(UserAgentMiddleware):
'''
隨機UA代理,中間件
'''
def process_request(self, request, spider):
'''
所有的請求都會經過process_request
:param request:請求
:param spider:爬蟲名
:return:
'''
ua = random.choice(USER_AGENTS)
request.headers.setdefault("User-Agent", ua)
class RandomIPMiddleware(HttpProxyMiddleware):
'''
隨機IP代理
'''
def process_request(self, request, spider):
proxy = random.choice(PROXIES)
request.meta['proxy'] = 'http://' + proxy['ip_port']
#class RandomCookieMiddleware(CookiesMiddleware):
# '''
# 隨機cookie池
# '''
#
# def process_request(self, request, spider):
# cookie = random.choice(COOKIES)
# request.cookies = cookie
在settings.py中添加:
# -*- coding: utf-8 -*-
# Obey robots.txt rules
ROBOTSTXT_OBEY = False
# Disable cookies (enabled by default)
COOKIES_ENABLED = False
# Override the default request headers:
DEFAULT_REQUEST_HEADERS = {
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Language': 'en',
'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36',
}
# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
#啓用中間件
DOWNLOADER_MIDDLEWARES = {
# 'weixinsougou.middlewares.WeixinsougouDownloaderMiddleware': 543,
'weixinsougou.middlewares.RandomUAMiddleware': 543,
'weixinsougou.middlewares.RandomIPMiddleware': 544,
}
#UA池
USER_AGENTS = [
"Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 2.0.50727; Media Center PC 6.0)",
"Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.0.3705; .NET CLR 1.1.4322)",
"Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.2; .NET CLR 3.0.04506.30)",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN) AppleWebKit/523.15 (KHTML, like Gecko, Safari/419.3) Arora/0.3 (Change: 287 c9dfb30)",
"Mozilla/5.0 (X11; U; Linux; en-US) AppleWebKit/527+ (KHTML, like Gecko, Safari/419.3) Arora/0.6",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.2pre) Gecko/20070215 K-Ninja/2.1.1",
"Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9) Gecko/20080705 Firefox/3.0 Kapiko/3.0",
"Mozilla/5.0 (X11; Linux i686; U;) Gecko/20070322 Kazehakase/0.4.5"
]
#IP池
PROXIES = [
{'ip_port': '171.38.85.93:8123'},
{'ip_port': '113.67.227.143:8118'},
{'ip_port': '101.236.19.165:8866'},
{'ip_port': '101.236.21.22:8866'},
]
#cookle池
COOKIES = []
# 默認線程數量 10
REACTOR_THREADPOOL_MAXSIZE = 20
# 併發 默認16
CONCURRENT_REQUESTS = 16
# pipelines同時處理數量 默認100
CONCURRENT_ITEMS = 50
# scrapy 深度爬取,默認0 不做深度限制
DEPTH_LIMIT = 4
# 下載超時
DOWNLOAD_TIMEOUT = 180
#####6、使用redis實現分佈式爬取
https://blog.csdn.net/lm_is_dc/article/details/81866275
#####7、部署
https://blog.csdn.net/lm_is_dc/article/details/81869508
8、使用gerapy管理爬蟲
https://blog.csdn.net/lm_is_dc/article/details/81869508
後記
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