Upgrade python2 to python3 and python2 to python3.

Upgrade python2 to python3 and python2 to python3.

Centos 6.5 System Environment
Python 2.6.6
Target python version 3.5.1
1. Download python3.5
Wget -- no-check-certificate http://www.python.org/ftp/python/3.3.0/Python-3.3.0.tgz
2. decompress the file for compilation and Installation
Tar-xvzf Python-3.3.0.tgz
Cd Python-3.3.0
./Configure -- prefix =/home/python/soft_install/python3.3/
Make
Make install
Go to the bin directory under the installation directory and check whether the installation is successful.
./Python3.3-V --- if the installation is successful, the version number is displayed.
Modify the default python and recreate the soft link.
Ln-s/home/python/soft_install/python3.3/bin/python3.3/usr/bin/python