centos6装python3，并安装requests, lxml和beautifulsoup模块

 一.  安装python3并设为默认版本，与python2共存

1、下载Python3.4安装包

   wget https://www.python.org/ftp/python/3.4.4/Python-3.4.4.tgz

2、解压、编译、安装

     yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make

  tar zxvf Python-3.4.4.tgz
  cd Python-3.4.4
  ./configure --prefix=/usr/local/python3
  make
  make install

3、创建Python3.4的链接,并且设置python3为默认版本（CentOS6.7默认安装的是Python2）

     cd /usr/bin/

     ln -s /usr/local/python3/bin/python3.4 python   #如果不想为默认版本，把python改为python3

4.  因为执行yum需要python2版本，所以我们还要修改yum的配置

     vi /usr/bin/yum 把#! /usr/bin/python修改为#! /usr/bin/python2

二.  安装模块

1. 安装beautifulsoup

   wget https://www.crummy.com/software/BeautifulSoup/bs4/download/4.5/beautifulsoup4-4.5.1.tar.gz

   tar xvzf beautifulsoup4-4.5.1.tar.gz

   cd beautifulsoup4-4.5.1 

   python setup.py install

2. 安装requests

   wget https://bootstrap.pypa.io/get-pip.py

   python get-pip.py 

   pip install requests

 

3. 安装lxml，依赖有libxml2-devel，libxslt-devel

    yum install libxml2-devel libxslt-devel -y

    pip install lxml