scrapy-redis分布式爬虫去重异步写入mysql数据库实例代码_异步redis爬虫案例

首先创建一个爬虫文件dgrds.py

# -*- coding: utf-8 -*-
import scrapy
from scrapy_redis.spiders import RedisSpider
class DgrdsSpider(RedisSpider):
    name = 'dgrds'
    redis_key = 'dgrds:start_urls'
 
    def parse(self, response):
        for i in range(2499930, 2499940):
            yield scrapy.Request('https://www.douguo.com/cookbook/' + str(i) + '.html', callback=self.parse2)
 
    def parse2(self, response):
        if (response.status == 200):
            title = response.css('.rinfo h1.title::text').get('')
            view_nums = response.css('.vcnum span:first-of-type::text').get('')
            collection_nums = response.css('.vcnum .collectnum::text').get('')
            user_name = response.css('.author-info .nickname::text').get('')
            user_image = response.css('.author-img img::attr(src)').get('')
            tags = ''
            tag_arr = response.css('.fenlei span')
            if tag_arr is not None:
                for tg in tag_arr:
                    tags += ';' + tg.css('a::text').get('')
            basic_url = ''
            youku = ''
            id = 0
            isvideo = response.css('#banner + a')
            if isvideo is not None:
                next_url = response.css('#banner + a::attr(href)').get('')
                id = next_url.replace('/recipevideo/', '')
                basic_url = 'https://www.douguo.com/cookbook/' + id + '.html'
                item = {
                    'cate': '',
                    'title': title,
                    'view_nums': view_nums,
                    'collection_nums': collection_nums,
                    'user_name': user_name,
                    'user_image': user_image,
                    'tags': tags,
                    'basic_url': basic_url
                }
                yield scrapy.Request(response.urljoin(next_url), meta=item, callback=self.parse4)
 
    def parse4(self, response):
        url = response.css('embed::attr(src)').get('')
        item = {
            'cate': response.meta['cate'],
            'title': response.meta['title'],
            'view_nums': response.meta['view_nums'],
            'collection_nums': response.meta['collection_nums'],
            'user_name': response.meta['user_name'],
            'user_image': response.meta['user_image'],
            'tags': response.meta['tags'],
            'basic_url': response.meta['basic_url']
        }
        item['video_url'] = url
        yield item

然后修改setting.py配置文件

# -*- coding: utf-8 -*-
 
# Scrapy settings for dgredis project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
#     https://docs.scrapy.org/en/latest/topics/settings.html
#     https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#     https://docs.scrapy.org/en/latest/topics/spider-middleware.html
 
BOT_NAME = 'dgredis'
 
SPIDER_MODULES = ['dgredis.spiders']
NEWSPIDER_MODULE = 'dgredis.spiders'
 
 
# Crawl responsibly by identifying yourself (and your website) on the user-agent
#USER_AGENT = 'dgredis (+http://www.yourdomain.com)'
 
# Obey robots.txt rules
ROBOTSTXT_OBEY = False
 
# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32
 
# Configure a delay for requests for the same website (default: 0)
# See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
#DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
#CONCURRENT_REQUESTS_PER_IP = 16
 
# Disable cookies (enabled by default)
#COOKIES_ENABLED = False
 
# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_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',
#}
 
# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
#    'dgredis.middlewares.DgredisSpiderMiddleware': 543,
#}
 
# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
#    'dgredis.middlewares.DgredisDownloaderMiddleware': 543,
#}
 
# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
#    'scrapy.extensions.telnet.TelnetConsole': None,
#}
 
# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
ITEM_PIPELINES = {
    'dgredis.pipelines.DgredisPipeline': 300,
    'scrapy_redis.pipelines.RedisPipeline': 400,
}
 
# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/autothrottle.html
#AUTOTHROTTLE_ENABLED = True
# The initial download delay
#AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False
 
# Enable and configure HTTP caching (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'
MYSQL_HOST = '127.0.0.1'
MYSQL_PORT = '3306'
MYSQL_USER = 'root'
MYSQL_PASS = ''
MYSQL_DB = 'test'
HTTPERROR_ALLOWED_CODES = [404, 301]
DUPEFILTER_CLASS = "scrapy_redis.dupefilter.RFPDupeFilter"
SCHEDULER = "scrapy_redis.scheduler.Scheduler"
SCHEDULER_PERSIST = True
#SCHEDULER_QUEUE_CLASS = "scrapy_redis.queue.SpiderPriorityQueue"
#SCHEDULER_QUEUE_CLASS = "scrapy_redis.queue.SpiderQueue"
#SCHEDULER_QUEUE_CLASS = "scrapy_redis.queue.SpiderStack"
 
LOG_LEVEL = 'DEBUG'
 
# Introduce an artifical delay to make use of parallelism. to speed up the
# crawl.
DOWNLOAD_DELAY = 1

然后修改管道文件pipeline.py

# -*- coding: utf-8 -*-
 
# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
import pymysql
from twisted.enterprise import adbapi
 
class DgredisPipeline:
    def __init__(self, dbpool):
        self.dbpool = dbpool
 
    @classmethod
    def from_settings(cls, settings):
        adbparams = dict(
            host=settings['MYSQL_HOST'],
            db=settings['MYSQL_DB'],
            user=settings['MYSQL_USER'],
            password=settings['MYSQL_PASS'],
            charset='utf8',
            cursorclass=pymysql.cursors.DictCursor
        )
        dbpool = adbapi.ConnectionPool('pymysql', **adbparams)
        return cls(dbpool)
 
    def process_item(self, item, spider):
        query = self.dbpool.runInteraction(self.do_insert, item)  # 指定操作方法和操作数据
        # 添加异常处理
        query.addCallback(self.handle_error)  # 处理异常
 
    def do_insert(self, cursor, item):
        # 对数据库进行插入操作，并不需要commit，twisted会自动commit
        insert_sql = """
        insert into douguoaa(title,user_name,user_image,view_nums,collection_nums,basic_url,video_url,tags,cate_name) VALUES(%s,%s,%s,%s,%s,%s,%s,%s,%s)
                    """
        cursor.execute(insert_sql, (
            item['title'], item['user_name'], item['user_image'], item['view_nums'], item['collection_nums'],
            item['basic_url'],
            item['video_url'], item['tags'], item['cate']))
 
    def handle_error(self, failure):
        if failure:
            print(failure)

修改完这三个文件就可以支持分布式爬取。去重。异步写入数据库功能了

cd切换到爬虫项目的spider文件夹，执行命令 scrapy runspider dgrds.py ,这时候爬虫出去等待发送指令状态

然后在redis-cli端发送爬取指令，也就是指定start_urls，命令：lpush dgrds:start_urls http://www.douguo.com，点击回车后上面的图片代码接收到指令后会自动执行爬取

这个是基础爬虫文件，规则爬取crawSpider跟这个类似，只需指定Rule规则即可

That's All

Thanks！