pyenv 安装

　sudo yum install openssl*
     git clone https://github.com/yyuu/pyenv.git ~/.pyenv
     echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
     echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
     echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
     exec $SHELL
     source ~/.bash_profile
     pyenv install -v 3.6.4
     python
     pyenv versions
     pyenv global 3.6.4
     python