Python2 upgrade into Python3

System Environment CentOS 6.5
Original Python version 2.6.6
Target Python version 3.5.1
1. Download python3.5
wget--no-check-certificate
2. Unzip the file to compile and install
  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 to check if the installation was successful
  ./python3.3-v    ---Displays the installed version number if the installation is successful
  Modify the default Python, re-establish the soft link
  Ln-s/home/python/soft_install/python3.3/bin/python3.3/usr/bin/python