如果已经安装python-dev和libxml，在开发环境OS X和ubuntu上安装scrapy非常简单：sudo esay_install scarpy。

但在CentOS5.8上安装碰到了一点小麻烦。

  [root@localhost ~]# easy_install scrapy
  Searching for scrapy
  Best match: Scrapy 0.16.1
  Processing Scrapy-0.16.1-py2.7.egg
  Scrapy 0.16.1 is already the active version in easy-install.pth
  Installing scrapy script to /usr/local/bin

  Using /usr/local/lib/python2.7/site-packages/Scrapy-0.16.1-py2.7.egg
  Processing dependencies for scrapy
  Searching for pyOpenSSL
  ......
  OpenSSL/ssl/connection.c:313: 错误：‘TLSEXT_NAMETYPE_host_name’ 未声明 (在此函数内第一次使用)
  OpenSSL/ssl/connection.c:313: 错误：(即使在一个函数内多次出现，每个未声明的标识符在其
  OpenSSL/ssl/connection.c:313: 错误：所在的函数内只报告一次。)
  ......
  error: Setup script exited with error: command 'gcc' failed with exit status 1

看起来是openssl的问题，要升级之，用easy_install，yum之类的安装一遍，不管用，最后没招，直接下源码安装：http://pypi.python.org/packages/source/p/pyOpenSSL/pyOpenSSL-0.12.tar.gz

  [root@localhost ~]# cd pyOpenSSL-0.12
  [root@localhost ~]# python setup.py install
  [root@localhost ~]# easy_install scrapy

搞定。