一、python3安装
1、cd /usr/bin
2、mv python python.bak
3、https://www.python.org/ftp/python/网站选择合适的版本
4、wget https://www.python.org/ftp/python/3.6.x/Python-3.6.x.tar.xz
5、tar -xvJf Python-3.6.2.tar.xz
6、cd Python-3.6.x
7、./configure prefix=/usr/local/python3
8、make && make install
9、ln -s /usr/local/python3/bin/python3 /usr/bin/python
二、解决yum不能使用问题：
a、vi /usr/bin/yum
b、vi /usr/libexec/urlgrabber-ext-down
c、将首行python改为python2.7
三、模块安装
1、scrapy
a、yum -y install epel-release
b、yum install -y python-pip
c、yum install -y python-devel
d、pip install scrapy
2、scrapy-redis
a、pip install scrapy-redis