1.Scrapy安装问题
一开始是按照官方文档上直接用pip安装的，创建项目的时候并没有报错，
然而在运行 scrapy crawl dmoz 的时候错误百粗/(ㄒoㄒ)/~~比如：
ImportError: No module named _cffi_backend
Unhandled error in Deferred 等等,发现是依赖包好多没有装上，就去百度安装各种包，
有好多大神把这些都总结好了：膜拜！^_^
http://blog.csdn.net/niying/article/details/27103081
http://blog.csdn.net/pleasecallmewhy/article/details/19354723
2.没有得到数据，发现是拼写错误.
E:\tutorial>scrapy crawl dmoz
2015-10-30 13:44:02 [scrapy] INFO: Scrapy 1.0.3 started (bot: tutorial)
2015-10-30 13:44:02 [scrapy] INFO: Optional features available: ssl, http11
2015-10-30 13:44:02 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'tu
torial.spiders', 'SPIDER_MODULES': ['tutorial.spiders'], 'BOT_NAME': 'tutorial'} 2015-10-30 13:44:02 [scrapy] INFO: Enabled extensions: CloseSpider, TelnetConsol
e, LogStats, CoreStats, SpiderState
2015-10-30 13:44:03 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddl
eware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultH
eadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMidd
leware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-10-30 13:44:03 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddlewa
re, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2015-10-30 13:44:03 [scrapy] INFO: Enabled item pipelines:
2015-10-30 13:44:03 [scrapy] INFO: Spider opened
2015-10-30 13:44:03 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 i
tems (at 0 items/min)
2015-10-30 13:44:03 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2015-10-30 13:44:03 [scrapy] INFO: Closing spider (finished)
2015-10-30 13:44:03 [scrapy] INFO: Dumping Scrapy stats:
{'finish_reason': 'finished',
'finish_time': datetime.datetime(2015, 10, 30, 5, 44, 3, 292000),
'log_count/DEBUG': 1,
'log_count/INFO': 7,
'start_time': datetime.datetime(2015, 10, 30, 5, 44, 3, 282000)}
2015-10-30 13:44:03 [scrapy] INFO: Spider closed (finished)
在spiders目录下的dmoz_spiders.py文件中将start_urls写成了start_url ，哎，╮(╯▽╰)╭
start_urls = [
"http://www.dmoz.org/Computers/Programming/Languages/Python/Books/",
"http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/"
]