scrapy是目前准备要学习的爬虫框架，其在ubuntu14.04下的安装过程如下：
ubuntu14.04下默认安装了2.7的python以及setuptools，若未安装，可通过下面指令安装：
sudo apt-get install python
sudo apt-get install python-setuptools
然后安装Twisted：
sudo apt-get install python-twisted
然后是Scrapy：
sudo apt-get install python-scrapy
安装完成后，如果直接键入scrapy启动的话会报类似如下错误：
File "/usr/local/bin/scrapy", line , in <module>
from pkg_resources import load_entry_point ...... pkg_resources.ContextualVersionConflict: (pyasn1 0.1. (/usr/lib/python2./dist-packages), Requirement.parse('pyasn1>=0.1.8'), set(['pyasn1-modules']))
按提示是个版本依赖的错误。
此时先安装pip：
sudo apt-get install python-pip
升级pip：
sudo pip install --upgrade pip
然后对提示的pyasn1升级：
sudo pip install --upgrade pyasn1
再启动scrapy就可以成功了：
Scrapy 1.0. - no active project Usage:
scrapy <command> [options] [args] Available commands:
bench Run quick benchmark test
commands
fetch Fetch a URL using the Scrapy downloader
runspider Run a self-contained spider (without creating a project)
settings Get settings values
shell Interactive scraping console
startproject Create new project
version Print Scrapy version
view Open URL in browser, as seen by Scrapy [ more ] More commands available when run from project directory Use "scrapy <command> -h" to see more info about a command