安装scrapy框架

1. install python2.7
   centos :
   https://github.com/h2oai/h2o/wiki/Installing-python-2.7-on-centos-6.3.-Follow-this-sequence-exactly-for-centos-machine-only
   Or
   yum groupinstall "Development tools"
   yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel libxslt-devel libxml2-devel
   cd Python-2.7.*
   ./configure --prefix=/usr/local --enable-unicode=ucs4 --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
   make -j4 && make altinstall
   ln -svf /usr/local/bin/python2.7 /usr/local/bin/python
   
   suse:
   #!/bin/bash
   # Install Python 2.7.2 alternatively
   
   zypper install -t pattern sdk_c_c++
   zypper install readline-devel openssl-devel gmp-devel ncurses-devel gdbm-devel zlib-devel expat-devel libGL-devel tk tix gcc-c++ libX11-devel glibc-devel bzip2     tar tcl-devel tk-devel pkgconfig tix-devel bzip2-devel sqlite-devel autoconf db4-devel libffi-devel valgrind-devel
   mkdir tmp
   cd tmp
   wget http://python.org/ftp/python/2.7.2/Python-2.7.2.tgz
   tar xvfz Python-2.7.2.tgz
   cd Python-2.7.2
   ./configure --prefix=/opt/python2.7 --enable-shared
   make -j4 && make altinstall
   echo "/opt/python2.7/lib" >> /etc/ld.so.conf.d/opt-python2.7.conf
   ldconfig
   cd ../..
   rm -rf tmp
   install setuptools:
   https://pypi.python.org/pypi/setuptools#unix-wget
   
   2. install pip
   https://scrapy-chs.readthedocs.org/zh_CN/0.24/intro/install.html#intro-install
    wget "https://bootstrap.pypa.io/get-pip.py" --no-check-certificate

   python get-pip.py

   
   3.
   yum install libffi* -y
   install scrapy and start demo
   
   https://scrapy-chs.readthedocs.org/zh_CN/0.24/intro/tutorial.html
   scrapy crawl demo -o item.json
   
   4. 模拟浏览器行为
   其一个执行js获取结果，需要清楚js执行逻辑
   其二个模拟浏览器UI动作，获得结果
   其余 （http://www.quora.com/How-can-we-execute-javascript-in-scrapy）
   4_1. scrapyJS
   http://splash.readthedocs.org/en/latest/
    install splash first and install scrapyJS
    a. http://splash.readthedocs.org/en/latest/install.html
       yum -y remove docker
       yum install docker-io （docker 运行以来内核版本2.6.32-431 及以上，如centos 6.5以上,  命令 docker -d 输出信息 ）
    b. pip install scrapyjs