我想弄清楚scrapy和泼水.作为练习,我尝试在下面的javascript网站上点击按钮:http://thestlbrowns.com/然后返回新渲染页面的html.
我的代码看起来像这样:
import scrapy import json from scrapy import Request class MySpider(scrapy.Spider): name = 'spiderman' domain = ['web'] start_urls = ['http://thestlbrowns.com/'] def start_requests(self): script = """ function main(splash) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(1)) assert(splash:runjs("$('#title.play-ball > a:first-child').click()")) assert(splash:wait(1)) -- return result as a JSON object return { html = splash:html(), -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end """ for url in self.start_urls: yield Request(url, self.parse, meta={'splash': {'args':{'lua_source': script},'endpoint':'execute',}}) def parse(self, response): splash_json = json.loads(response.body_as_unicode())
但是,当我运行此代码时,我得到以下输出:
$ scrapy crawl spiderman 2017-01-12 14:19:03 [scrapy.utils.log] INFO: Scrapy 1.3.0 started (bot: myScrapingProject) 2017-01-12 14:19:03 [scrapy.utils.log] INFO: Overridden settings: {'BOT_NAME': 'myScrapingProject', 'DOWNLOAD_DELAY': 0.25, 'DUPEFILTER_CLASS': 'scrapy_splash.SplashAwareDupeFilter', 'HTTPCACHE_STORAGE': 'scrapy_splash.SplashAwareFSCacheStorage', 'NEWSPIDER_MODULE': 'myScrapingProject.spiders', 'SPIDER_MODULES': ['myScrapingProject.spiders'], 'USER_AGENT': 'Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20100101 Firefox/7.7'} 2017-01-12 14:19:03 [scrapy.middleware] INFO: Enabled extensions: ['scrapy.extensions.corestats.CoreStats', 'scrapy.extensions.telnet.TelnetConsole', 'scrapy.extensions.logstats.LogStats'] 2017-01-12 14:19:03 [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.redirect.RedirectMiddleware', 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware', 'scrapy_splash.SplashCookiesMiddleware', 'scrapy_splash.SplashMiddleware', 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware', 'scrapy.downloadermiddlewares.stats.DownloaderStats'] 2017-01-12 14:19:03 [scrapy.middleware] INFO: Enabled spider middlewares: ['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware', 'scrapy_splash.SplashDeduplicateArgsMiddleware', 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware', 'scrapy.spidermiddlewares.referer.RefererMiddleware', 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware', 'scrapy.spidermiddlewares.depth.DepthMiddleware'] 2017-01-12 14:19:03 [scrapy.middleware] INFO: Enabled item pipelines: [] 2017-01-12 14:19:03 [scrapy.core.engine] INFO: Spider opened 2017-01-12 14:19:03 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min) 2017-01-12 14:19:03 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:6023 2017-01-12 14:19:16 [scrapy_splash.middleware] WARNING: Bad request to Splash: {'error': 400, 'info': {'error': "bad argument #2 to 'assert' (string expected, got table)", 'line_number': 8, 'source': '[string "..."]', 'message': 'Lua error: [string "..."]:8: bad argument #2 to \'assert\' (string expected, got table)', 'type': 'LUA_ERROR'}, 'description': 'Error happened while executing Lua script', 'type': 'ScriptError'} 2017-01-12 14:19:16 [scrapy.core.engine] DEBUG: Crawled (400)(referer: None) 2017-01-12 14:19:16 [scrapy.spidermiddlewares.httperror] INFO: Ignoring response <400 http://thestlbrowns.com/>: HTTP status code is not handled or not allowed 2017-01-12 14:19:16 [scrapy.core.engine] INFO: Closing spider (finished) 2017-01-12 14:19:16 [scrapy.statscollectors] INFO: Dumping Scrapy stats: {'downloader/request_bytes': 1222, 'downloader/request_count': 1, 'downloader/request_method_count/POST': 1, 'downloader/response_bytes': 471, 'downloader/response_count': 1, 'downloader/response_status_count/400': 1, 'finish_reason': 'finished', 'finish_time': datetime.datetime(2017, 1, 12, 13, 19, 16, 846242), 'log_count/DEBUG': 2, 'log_count/INFO': 8, 'log_count/WARNING': 1, 'response_received_count': 1, 'scheduler/dequeued': 2, 'scheduler/dequeued/memory': 2, 'scheduler/enqueued': 2, 'scheduler/enqueued/memory': 2, 'splash/execute/request_count': 1, 'splash/execute/response_count/400': 1, 'start_time': datetime.datetime(2017, 1, 12, 13, 19, 3, 417278)} 2017-01-12 14:19:16 [scrapy.core.engine] INFO: Spider closed (finished)
问:有谁知道如何解决这个/我做错了什么?
编辑:当我script = quote(script)
在将脚本传递给splash之前添加时,我得到以下错误输出:
Message: 'Bad request to Splash: {\'type\': \'ScriptError\', \'description\': \'Error happened while executing Lua script\', ' \ '\'error\': 400, \'info\': {\'error\': "unexpected symbol near \'%\'", \'type\': \'LUA_INIT_ERROR\', \'line_number\': 1, ' \ '\'source\': \'[string "%0A%20%20%20%20%20%20%20%20%20function%20main..."]\',' \ ' \'message\': \'[string "%0A%20%20%20%20%20%20%20%20%20function%20main..."]:1: unexpected symbol near \\\'%\\\'\'}}'
paul trmbrth.. 7
Splash响应确实包含一些提示:
{'description': 'Error happened while executing Lua script', 'error': 400, 'info': {'error': "bad argument #2 to 'assert' (string expected, got table)", 'line_number': 8, 'message': 'Lua error: [string "..."]:8: bad argument #2 to \'assert\' (string expected, got table)', 'source': '[string "..."]', 'type': 'LUA_ERROR'}, 'type': 'ScriptError'}
如果你在Splash的web界面中尝试你的脚本(这是你的朋友!),你会遇到同样的错误,来自这一行:
assert(splash:runjs("$('#title.play-ball > a:first-child').click()"))
如果你稍微改变一下Lua脚本,那就抓住错误(顺便说一下,我相信你的意思是.title.play-ball > a:first-child
因为没有元素id="title"
):
function main(splash) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(1)) -- go back 1 month in time and wait a little (1 second) ok, err = splash:runjs("$('.title.play-ball > a:first-child').click()") assert(splash:wait(1)) -- return result as a JSON object return { html = splash:html(), error = err -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
并在Web界面中运行它,您在响应中得到一个"错误"对象,其中显示:
error: Object js_error: "ReferenceError: Can't find variable: $" js_error_message: "Can't find variable: $" js_error_type: "ReferenceError" message: "JS error: \"ReferenceError: Can't find variable: $\"" splash_method: "runjs" type: "JS_ERROR"
看起来$
魔术并不适用于该网站.例如,你可以在Chrome控制台中使用它,但是使用Splash你可能/显然需要加载jQuery(或类似的东西),splash:autoload
通常.例如:
function main(splash) assert(splash:autoload("https://code.jquery.com/jquery-3.1.1.min.js")) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(1)) -- go back 1 month in time and wait a little (1 second) ok, err = splash:runjs("$('.title.play-ball > a:first-child').click()") assert(splash:wait(1)) -- return result as a JSON object return { html = splash:html(), error = err -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
请注意,这个JavaScript代码对我来说不适用于Splash(截图没有显示"历史记录"的内容).
但我尝试在网络界面中使用以下内容,然后我获得了"历史"节目(在png屏幕截图中 - 这里有评论):
function main(splash) -- no need to load jQuery when you use splash:select --assert(splash:autoload("https://code.jquery.com/jquery-3.1.1.min.js")) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(15)) local element = splash:select('.title.play-ball > a:first-child') local bounds = element:bounds() assert(element:mouse_click{x=bounds.width/2, y=bounds.height/2}) assert(splash:wait(5)) -- return result as a JSON object return { html = splash:html(), -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
实际上,Splash 2.3有这种交互的帮助(例如点击一个元素).请参阅例如splash:select和element:mouse_click
另请注意,我增加了wait()
值.
Splash响应确实包含一些提示:
{'description': 'Error happened while executing Lua script', 'error': 400, 'info': {'error': "bad argument #2 to 'assert' (string expected, got table)", 'line_number': 8, 'message': 'Lua error: [string "..."]:8: bad argument #2 to \'assert\' (string expected, got table)', 'source': '[string "..."]', 'type': 'LUA_ERROR'}, 'type': 'ScriptError'}
如果你在Splash的web界面中尝试你的脚本(这是你的朋友!),你会遇到同样的错误,来自这一行:
assert(splash:runjs("$('#title.play-ball > a:first-child').click()"))
如果你稍微改变一下Lua脚本,那就抓住错误(顺便说一下,我相信你的意思是.title.play-ball > a:first-child
因为没有元素id="title"
):
function main(splash) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(1)) -- go back 1 month in time and wait a little (1 second) ok, err = splash:runjs("$('.title.play-ball > a:first-child').click()") assert(splash:wait(1)) -- return result as a JSON object return { html = splash:html(), error = err -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
并在Web界面中运行它,您在响应中得到一个"错误"对象,其中显示:
error: Object js_error: "ReferenceError: Can't find variable: $" js_error_message: "Can't find variable: $" js_error_type: "ReferenceError" message: "JS error: \"ReferenceError: Can't find variable: $\"" splash_method: "runjs" type: "JS_ERROR"
看起来$
魔术并不适用于该网站.例如,你可以在Chrome控制台中使用它,但是使用Splash你可能/显然需要加载jQuery(或类似的东西),splash:autoload
通常.例如:
function main(splash) assert(splash:autoload("https://code.jquery.com/jquery-3.1.1.min.js")) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(1)) -- go back 1 month in time and wait a little (1 second) ok, err = splash:runjs("$('.title.play-ball > a:first-child').click()") assert(splash:wait(1)) -- return result as a JSON object return { html = splash:html(), error = err -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
请注意,这个JavaScript代码对我来说不适用于Splash(截图没有显示"历史记录"的内容).
但我尝试在网络界面中使用以下内容,然后我获得了"历史"节目(在png屏幕截图中 - 这里有评论):
function main(splash) -- no need to load jQuery when you use splash:select --assert(splash:autoload("https://code.jquery.com/jquery-3.1.1.min.js")) local url = splash.args.url assert(splash:go(url)) assert(splash:wait(15)) local element = splash:select('.title.play-ball > a:first-child') local bounds = element:bounds() assert(element:mouse_click{x=bounds.width/2, y=bounds.height/2}) assert(splash:wait(5)) -- return result as a JSON object return { html = splash:html(), -- we don't need screenshot or network activity --png = splash:png(), --har = splash:har(), } end
实际上,Splash 2.3有这种交互的帮助(例如点击一个元素).请参阅例如splash:select和element:mouse_click
另请注意,我增加了wait()
值.