python 基礎學習中對于scrapy的使用遇到了一些問題。

首先進行的是對Amazon.cn的檢索結果頁進行爬取，很順利，無礙。

下一個目標是對baidu的搜索結果進行爬取

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1，反爬蟲

1.1 我先對ROBOTSTXT_OBEY進行設置，結果找到了scrapy的默認參數（這里涉及多Python環境下庫的調用問題，又是一個坑，另寫一篇進行記錄）。修改無效。

詢問后才知道是對scrapy startproject編譯過的項目中的setting進行修改

1.2 反爬蟲第二關：網址，之前調用的

1 import scrapy 2 import sys 3 4 class Jizhi(scrapy.Spider): 5 6 name = 'jizhi' 7 8 arg = ' '.join(sys.argv[3:]) 9 10 base_urls = "https://www.baidu.com" 11 12 start_urls = [ 13 'https://www.baidu.com/s?{}'.format(arg) 14 ] 15 16 counter = 0 17 18 def parse(self, response): 19 20 result_lst = response.css("h3.t a::text") 21 22 for result in result_lst: 23 yield { 24 'title':result.extract() 25 } 26 27 Jizhi.counter +=1 28 29 # next_page:css('a.n') 30 31 if Jizhi.counter == 5: return 32 33 next_page = response.css('a.n::attr(href)') 34 35 if len(next_page) == 2: 36 next_page_url = next_page[1].extract() 37 else: 38 next_page_url = next_page.extract_first() 39 40 yield scrapy.Request(self.base_urls + next_page_url, callback=self.parse) 使用https

結果

2018-07-26 09:37:28 [scrapy.utils.log] INFO: Scrapy 1.5.0 started (bot: jizhi) 2018-07-26 09:37:28 [scrapy.utils.log] INFO: Versions: lxml 4.2.1.0, libxml2 2.9.8, cssselect 1.0.3, parsel 1.4.0, w3lib 1.19.0, Twisted 17.5.0, Python 3.6.5 |Anaconda, Inc.| (default, Mar 29 2018, 13:32:41) [MSC v.1900 64 bit (AMD64)], pyOpenSSL 18.0.0 (OpenSSL 1.0.2k 26 Jan 2017), cryptography 2.2.2, Platform Windows-10-10.0.17134-SP0 2018-07-26 09:37:28 [scrapy.crawler] INFO: Overridden settings: {'BOT_NAME': 'jizhi', 'NEWSPIDER_MODULE': 'jizhi.spiders', 'SPIDER_MODULES': ['jizhi.spiders']} 2018-07-26 09:37:29 [scrapy.middleware] INFO: Enabled extensions: ['scrapy.extensions.corestats.CoreStats','scrapy.extensions.telnet.TelnetConsole','scrapy.extensions.logstats.LogStats'] 2018-07-26 09:37:29 [scrapy.middleware] INFO: Enabled downloader middlewares: ['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'] 2018-07-26 09:37:29 [scrapy.middleware] INFO: Enabled spider middlewares: ['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware','scrapy.spidermiddlewares.offsite.OffsiteMiddleware','scrapy.spidermiddlewares.referer.RefererMiddleware','scrapy.spidermiddlewares.urllength.UrlLengthMiddleware','scrapy.spidermiddlewares.depth.DepthMiddleware'] 2018-07-26 09:37:29 [scrapy.middleware] INFO: Enabled item pipelines: [] 2018-07-26 09:37:29 [scrapy.core.engine] INFO: Spider opened 2018-07-26 09:37:29 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min) 2018-07-26 09:37:29 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:6023 2018-07-26 09:37:29 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.baidu.com/s?wd=jizhi> (referer: None) 2018-07-26 09:37:29 [scrapy.core.scraper] ERROR: Spider error processing <GET https://www.baidu.com/s?wd=jizhi> (referer: None) Traceback (most recent call last):File "C:\Users\asus\Anaconda3\lib\site-packages\scrapy\utils\defer.py", line 102, in iter_errbackyield next(it)File "C:\Users\asus\Anaconda3\lib\site-packages\scrapy\spidermiddlewares\offsite.py", line 30, in process_spider_outputfor x in result:File "C:\Users\asus\Anaconda3\lib\site-packages\scrapy\spidermiddlewares\referer.py", line 339, in <genexpr>return (_set_referer(r) for r in result or ())File "C:\Users\asus\Anaconda3\lib\site-packages\scrapy\spidermiddlewares\urllength.py", line 37, in <genexpr>return (r for r in result or () if _filter(r))File "C:\Users\asus\Anaconda3\lib\site-packages\scrapy\spidermiddlewares\depth.py", line 58, in <genexpr>return (r for r in result or () if _filter(r))File "C:\Users\asus\Documents\GitHub\spider\jizhi\jizhi\spiders\jizhi.py", line 40, in parseyield scrapy.Request(self.base_urls + next_page_url, callback=self.parse) TypeError: must be str, not NoneType 2018-07-26 09:37:29 [scrapy.core.engine] INFO: Closing spider (finished) 2018-07-26 09:37:29 [scrapy.statscollectors] INFO: Dumping Scrapy stats: {'downloader/request_bytes': 222,'downloader/request_count': 1,'downloader/request_method_count/GET': 1,'downloader/response_bytes': 872,'downloader/response_count': 1,'downloader/response_status_count/200': 1,'finish_reason': 'finished','finish_time': datetime.datetime(2018, 7, 26, 1, 37, 29, 585191),'log_count/DEBUG': 2,'log_count/ERROR': 1,'log_count/INFO': 7,'response_received_count': 1,'scheduler/dequeued': 1,'scheduler/dequeued/memory': 1,'scheduler/enqueued': 1,'scheduler/enqueued/memory': 1,'spider_exceptions/TypeError': 1,'start_time': datetime.datetime(2018, 7, 26, 1, 37, 29, 324887)} 2018-07-26 09:37:29 [scrapy.core.engine] INFO: Spider closed (finished) View Code

報錯，范圍值應該是str而不是NoneType，很疑惑為啥是NoneType

這一項是str，那說明后面的參數返回值為空，沒爬到數據。

ERROR: Spider error processing <GET https://www.baidu.com/s?wd=jizhi> (referer: None)

最后問來問去，是https的問題，把它換成http，OK了。

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轉載于:https://www.cnblogs.com/inkyang/p/9369880.html

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