Python安装升级教程

升级前安装依赖

yum groupinstall "Development tools"

Python 2.7.9 下载>解压>编译>安装

wget https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tgz 
tar jxvf Python-2.7.9.tgz   
mv Python-2.7.9  python
cd python
./configure --prefix=/usr/local/python
make && make altinstall

• 关于altinstall

   Warning
  make install can overwrite or masquerade the python binary. make altinstall is therefore recommended instead of make install since it only installs exec_prefix/bin/pythonversion.

修改系统默认Python

1. 查看已有python版本
   python -V
2. 查看Python版本
   /usr/local/python/bin/python2.7 -V
3. 将系统默认Python改为新安装的Python
   ln -fs /usr/local/python/bin/python2.7 /usr/bin/python

yum无法运行问题

进行更改后，yum会无法运行了。修改/usr/bin/yum文件，将第一行的
#!/usr/bin/python
中的python改为系统原有的python版本，如下：
#!/usr/bin/python2.6