15天學會爬蟲 第九天

爬蟲

第九天

scrapy debug信息

2019-01-19 09:50:48 [scrapy.utils.log] INFO: Scrapy 1.5.1 started (bot: tencent)
2019-01-19 09:50:48 [scrapy.utils.log] INFO: Versions: lxml 4.2.5.0, libxml2 2.9.5, cssselect 1.0.3, parsel 1.5.0, w3lib 1.19.0, Twisted 18.9.0, Python 3.6.5 (v3
.6.5:f59c0932b4, Mar 28 2018, 17:00:18) [MSC v.1900 64 bit (AMD64)], pyOpenSSL 18.0.0 (OpenSSL 1.1.0i  14 Aug 2018), cryptography 2.3.1, Platform Windows-10-10.0
.17134-SP0  ### 爬蟲scrpay框架依賴的相關模塊和平臺的信息
2019-01-19 09:50:48 [scrapy.crawler] INFO: Overridden settings: {'BOT_NAME': 'tencent', 'NEWSPIDER_MODULE': 'tencent.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MO
DULES': ['tencent.spiders'], 'USER_AGENT': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/53
7.36'}  ### 自定義的配置信息哪些被應用了
2019-01-19 09:50:48 [scrapy.middleware] INFO: Enabled extensions: ### 插件信息
['scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.logstats.LogStats']
2019-01-19 09:50:48 [scrapy.middleware] INFO: Enabled downloader middlewares: ### 啓動的下載器中間件
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2019-01-19 09:50:48 [scrapy.middleware] INFO: Enabled spider middlewares: ### 啓動的爬蟲中間件
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2019-01-19 09:50:48 [scrapy.middleware] INFO: Enabled item pipelines: ### 啓動的管道
['tencent.pipelines.TencentPipeline']
2019-01-19 09:50:48 [scrapy.core.engine] INFO: Spider opened ### 開始爬去數據
2019-01-19 09:50:48 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2019-01-19 09:50:48 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:6023
2019-01-19 09:50:51 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://hr.tencent.com/robots.txt> (referer: None)  ### 抓取robots協議內容
2019-01-19 09:50:51 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://hr.tencent.com/position.php?&start=#a0> (referer: None)  ### start_url發起請求
2019-01-19 09:50:51 [scrapy.spidermiddlewares.offsite] DEBUG: Filtered offsite request to 'hr.tencent.com': <GET https://hr.tencent.com/position.php?&start=>  ### 提示錯誤，爬蟲中通過yeid交給引擎的請求會經過爬蟲中間件，由於請求的url超出allowed_domain的範圍，被offsitmiddleware 攔截了
2019-01-19 09:50:51 [scrapy.core.engine] INFO: Closing spider (finished) ### 爬蟲關閉
2019-01-19 09:50:51 [scrapy.statscollectors] INFO: Dumping Scrapy stats: ### 本次爬蟲的信息統計
{'downloader/request_bytes': 630,
 'downloader/request_count': 2,
 'downloader/request_method_count/GET': 2,
 'downloader/response_bytes': 4469,
 'downloader/response_count': 2,
 'downloader/response_status_count/200': 2,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2019, 1, 19, 1, 50, 51, 558634),
 'log_count/DEBUG': 4,
 'log_count/INFO': 7,
 'offsite/domains': 1,
 'offsite/filtered': 12,
 'request_depth_max': 1,
 'response_received_count': 2,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'start_time': datetime.datetime(2019, 1, 19, 1, 50, 48, 628465)}
2019-01-19 09:50:51 [scrapy.core.engine] INFO: Spider closed (finished)

scrapy shell

• response.url：當前響應的url地址
• response.request.url：當前響應對應的請求的url地址
• response.headers：響應頭
• response.body：響應體，也就是html代碼，默認是byte類型
• response.requests.headers：當前響應的請求頭

scrapy setting

1. 獲取settings

   # 在爬蟲類中，使用實例對象的settings屬性即可
   class TtSpider(scrapy.Spider):
       def parse(self, response):
           host = self.settings.get['HOST']
   
   # 在管道中
   class TencentPipeline(object)：
       def process_item(self, item, spider):
           host = spider.settings.get['HOST']
   
   

2. setting.py的重要配置

• USER_AGENT 設置ua
• ROBOTSTXT_OBEY 是否遵守robots協議，默認是遵守
• CONCURRENT_REQUESTS 設置併發請求的數量，默認是16個
• DOWNLOAD_DELAY 下載延遲，默認無延遲
• COOKIES_ENABLED 是否開啓cookie，即每次請求帶上前一次的cookie，默認是開啓的
• DEFAULT_REQUEST_HEADERS 設置默認請求頭
• SPIDER_MIDDLEWARES 爬蟲中間件，設置過程和管道相同
• DOWNLOADER_MIDDLEWARES 下載中間件

open_spider和close_spider

from pymongo import MongoClient

class SavePipeline(object):
    def __init__(self):
        self.client = MongoClient()

    def open_spider(self, spider):  # spider.name 這個爬蟲開啓的時候，僅執行一次
        if spider.name == "sina":
            spider.col = self.client['news']['sina']
        elif spider.name == "163":
            spider.col = self.client['news']['163']

    def process_item(self, item, spider):
        spider.col.insert(item)
        return item

    def close_spider(self, spider):  # spider.name 這個爬蟲關閉的時候，僅執行一次
        pass