这些天应朋友的要求抓取某个论坛帖子的信息，网上搜索了一下开源的爬虫资料，看了许多对于开源爬虫的比较发现开源爬虫scrapy比较好用。但是以前一直用的java和php，对python不熟悉，于是花一天时间粗略了解了一遍python的基础知识。于是就开干了，没想到的配置一个运行环境就花了我一天时间。下面记录下安装和配置scrapy踩过的那些坑吧。
运行环境：CentOS 6.0 虚拟机
开始上来先得安装python运行环境。然而我运行了一下python命令，发现已经自带了，窃（大）喜（坑）。于是google搜索了一下安装步骤，pip install Scrapy直接安装，发现不对。少了pip，于是安装pip。再次pip install Scrapy，发现少了python-devel，于是这么来回折腾了一上午。后来下载了scrapy的源码安装，突然曝出一个需要python2.7版本，再通过python --version查看，一个2.6映入眼前；顿时千万个草泥马在心中奔腾。
于是查看了官方文档（http://doc.scrapy.org/en/master/intro/install.html），果然是要python2.7。没办法，只能升级python的版本了。
#wget https://www.python.org/ftp/python/2.7.10/Python-2.7.10.tgz#tar -zxvf Python-2.7.10.tgz#cd Python-2.7.10#./configure #make all #make install #make clean #make distclean
#python --version
发现还是2.6
#mv /usr/bin/python /usr/bin/python2.6.6_bak#ln -s /usr/local/bin/python2.7 /usr/bin/python
# python --versionPython 2.7.10
到这里，python算是升级完成了，继续安装scrapy。于是pip install scrapy，还是报错。
Collecting Twisted>=10.0.0 (from scrapy) Could not find a version that satisfies the requirement Twisted>=10.0.0 (from scrapy) (from versions: )No matching distribution found for Twisted>=10.0.0 (from scrapy)
少了 Twisted，于是安装Twisted
cd Twisted-15.2.1python setup.py install
pythonPython 2.7.10 (default, Jun 5 2015, 17:56:24) [GCC 4.4.4 20100726 (Red Hat 4.4.4-13)] on linux2Type "help", "copyright", "credits" or "license" for more information.>>> import twisted>>>
此时索命twisted已经安装成功。于是继续pip install scrapy，还是报错。
Collecting libxlst Could not find a version that satisfies the requirement libxlst (from versions: )No matching distribution found for libxlst
Collecting libxml2 Could not find a version that satisfies the requirement libxml2 (from versions: )No matching distribution found for libxml2
wget http://xmlsoft.org/sources/libxslt-1.1.28.tar.gzcd libxslt-1.1.28/./configuremakemake install
wget ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gzcd libxml2-2.9.2/./configuremakemake install
安装好以后继续pip install scrapy，幸运之星仍未降临
Failed building wheel for cryptography 下载cryptography（https://pypi.python.org/packages/source/c/cryptography/cryptography-0.4.tar.gz）
安装
cd cryptography-0.4python setup.py buildpython setup.py install
发现安装的时候报错：
No package 'libffi' found
于是下载libffi下载并安装
wget ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gzcd libffi-3.2.1makemake install
安装后发现仍然报错
Package libffi was not found in the pkg-config search path. Perhaps you should add the directory containing `libffi.pc' to the PKG_CONFIG_PATH environment variable No package 'libffi' found
于是设置：PKG_CONFIG_PATH
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH
再次安装scrapy
pip install scrapy 幸运女神都去哪儿了？
ImportError: libffi.so.6: cannot open shared object file: No such file or directory
于是
whereis libffilibffi: /usr/local/lib/libffi.a /usr/local/lib/libffi.la /usr/local/lib/libffi.so 已经正常安装，网上搜索了一通，发现是LD_LIBRARY_PATH没设置，于是
export LD_LIBRARY_PATH=/usr/local/lib
于是继续安装cryptography-0.4
./configuremakemake install
此时正确安装，没有报错信息了。
pip install scrapy 看着提示信息：
Building wheels for collected packages: cryptography Running setup.py bdist_wheel for cryptography
在这里停了好久，在想幸运女神是不是到了。等了一会
Requirement already satisfied (use --upgrade to upgrade): zope.interface>=3.6.0 in /usr/local/lib/python2.7/site-packages/zope.interface-4.1.2-py2.7-linux-i686.egg (from Twisted>=10.0.0->scrapy)Collecting cryptography>=0.7 (from pyOpenSSL->scrapy) Using cached cryptography-0.9.tar.gzRequirement already satisfied (use --upgrade to upgrade): setuptools in /usr/local/lib/python2.7/site-packages (from zope.interface>=3.6.0->Twisted>=10.0.0->scrapy)Requirement already satisfied (use --upgrade to upgrade): idna in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): pyasn1 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): enum34 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): ipaddress in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): cffi>=0.8 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): ordereddict in /usr/local/lib/python2.7/site-packages (from enum34->cryptography>=0.7->pyOpenSSL->scrapy)Requirement already satisfied (use --upgrade to upgrade): pycparser in /usr/local/lib/python2.7/site-packages (from cffi>=0.8->cryptography>=0.7->pyOpenSSL->scrapy)Building wheels for collected packages: cryptography Running setup.py bdist_wheel for cryptography Stored in directory: /root/.cache/pip/wheels/d7/64/02/7258f08eae0b9c930c04209959c9a0794b9729c2b64258117eSuccessfully built cryptographyInstalling collected packages: cryptography Found existing installation: cryptography 0.4 Uninstalling cryptography-0.4: Successfully uninstalled cryptography-0.4Successfully installed cryptography-0.9
显示如此的信息。看到此刻，内流马面。谢谢CCAV，感谢MTV，钓鱼岛是中国的。终于安装成功了。
创建测试脚本
cat > myspider.py <<EOFfrom scrapy import Spider, Item, Fieldclass Post(Item): title = Field()class BlogSpider(Spider): name, start_urls = 'blogspider', ['http://www.cnblogs.com/rwxwsblog/'] def parse(self, response): return [Post(title=e.extract()) for e in response.css("h2 a::text")]EOF
测试脚本能否正常运行
scrapy runspider myspider.py
2015-06-06 20:25:16 [scrapy] INFO: Scrapy 1.0.0rc2 started (bot: scrapybot)2015-06-06 20:25:16 [scrapy] INFO: Optional features available: ssl, http112015-06-06 20:25:16 [scrapy] INFO: Overridden settings: {}2015-06-06 20:25:16 [py.warnings] WARNING: :0: UserWarning: You do not have a working installation of the service_identity module: 'No module named service_identity'. Please install it from <https://pypi.python.org/pypi/service_identity> and make sure all of its dependencies are satisfied. Without the service_identity module and a recent enough pyOpenSSL to support it, Twisted can perform only rudimentary TLS client hostname verification. Many valid certificate/hostname mappings may be rejected.2015-06-06 20:25:16 [scrapy] INFO: Enabled extensions: CloseSpider, TelnetConsole, LogStats, CoreStats, SpiderState2015-06-06 20:25:16 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats2015-06-06 20:25:16 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware2015-06-06 20:25:16 [scrapy] INFO: Enabled item pipelines: 2015-06-06 20:25:16 [scrapy] INFO: Spider opened2015-06-06 20:25:16 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)2015-06-06 20:25:16 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:60232015-06-06 20:25:17 [scrapy] DEBUG: Crawled (200) <GET http://www.cnblogs.com/rwxwsblog/> (referer: None)2015-06-06 20:25:17 [scrapy] INFO: Closing spider (finished)2015-06-06 20:25:17 [scrapy] INFO: Dumping Scrapy stats:{'downloader/request_bytes': 226, 'downloader/request_count': 1, 'downloader/request_method_count/GET': 1, 'downloader/response_bytes': 5383, 'downloader/response_count': 1, 'downloader/response_status_count/200': 1, 'finish_reason': 'finished', 'finish_time': datetime.datetime(2015, 6, 6, 12, 25, 17, 310084), 'log_count/DEBUG': 2, 'log_count/INFO': 7, 'log_count/WARNING': 1, 'response_received_count': 1, 'scheduler/dequeued': 1, 'scheduler/dequeued/memory': 1, 'scheduler/enqueued': 1, 'scheduler/enqueued/memory': 1, 'start_time': datetime.datetime(2015, 6, 6, 12, 25, 16, 863599)}2015-06-06 20:25:17 [scrapy] INFO: Spider closed (finished)
运行正常（此时心中窃喜，^_^....）。
scrapy startproject tutorial
输出以下信息
Traceback (most recent call last): File "/usr/local/bin/scrapy", line 9, in <module> load_entry_point('Scrapy==1.0.0rc2', 'console_scripts', 'scrapy')() File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 552, in load_entry_point return get_distribution(dist).load_entry_point(group, name) File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2672, in load_entry_point return ep.load() File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2345, in load return self.resolve() File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2351, in resolve module = __import__(self.module_name, fromlist=['__name__'], level=0) File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/__init__.py", line 48, in <module> from scrapy.spiders import Spider File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/spiders/__init__.py", line 10, in <module> from scrapy.http import Request File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/http/__init__.py", line 11, in <module> from scrapy.http.request.form import FormRequest File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/http/request/form.py", line 9, in <module> import lxml.html File "/usr/local/lib/python2.7/site-packages/lxml/html/__init__.py", line 42, in <module> from lxml import etreeImportError: /usr/lib/libxml2.so.2: version `LIBXML2_2.9.0' not found (required by /usr/local/lib/python2.7/site-packages/lxml/etree.so)
心中无数个草泥马再次狂奔。怎么又不行了？难道会变戏法？定定神看了下：ImportError: /usr/lib/libxml2.so.2: version `LIBXML2_2.9.0' not found (required by /usr/local/lib/python2.7/site-packages/lxml/etree.so)。这是那样的熟悉呀！想了想，这怎么和前面的ImportError: libffi.so.6: cannot open shared object file: No such file or directory那么类似呢？于是
export LD_LIBRARY_PATH=/usr/local/lib
再次运行：
scrapy startproject tutorial
输出以下信息：
[root@bogon scrapy]# scrapy startproject tutorial2015-06-06 20:35:43 [scrapy] INFO: Scrapy 1.0.0rc2 started (bot: scrapybot)2015-06-06 20:35:43 [scrapy] INFO: Optional features available: ssl, http112015-06-06 20:35:43 [scrapy] INFO: Overridden settings: {}New Scrapy project 'tutorial' created in: /root/scrapy/tutorialYou can start your first spider with: cd tutorial scrapy genspider example example.com
尼玛的终于成功了。由此可见，scrapy运行的时候需要 LD_LIBRARY_PATH环境变量的支持。可以考虑将其加入环境变量中
vi /etc/profile 添加：export LD_LIBRARY_PATH=/usr/local/lib 这行（前面的PKG_CONFIG_PATH也可以考虑添加进来，export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH）
保存后检查是否存在异常：
source /etc/profile
开一个新的会话运行
scrapy runspider myspider.py
发现正常运行，可见LD_LIBRARY_PATH是生效的。至此scrapy就算正式安装成功了。
查看scrapy版本：运行scrapy version，看了下scrapy的版本为“Scrapy 1.0.0rc2”
9、编程外的思考(感谢阅读到此的你，我自己都有点晕了。)
http://scrapy.org/
http://doc.scrapy.org/en/master/
http://blog.csdn.net/slvher/article/details/42346887
http://blog.csdn.net/niying/article/details/27103081
http://www.cnblogs.com/xiaoruoen/archive/2013/02/27/2933854.html
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