brew install pyenv

[^1] brew下载pyenv时，可能遇到403，无法解析，原因是DNS解析被污染，在/etc/hosts文件中添加

199.232.68.133 raw.githubusercontent.com
199.232.68.133 user-images.githubusercontent.com
199.232.68.133 avatars2.githubusercontent.com
199.232.68.133 avatars1.githubusercontent.com

1. brew install pyenv
2. vim ~/.bash_profile

export PYENV_ROOT=/usr/local/var/pyenv
export PATH="$PYENV_ROOT/shims:$PATH"
if command -v pyenv 1>/dev/null 2>&1; then eval "$(pyenv init -)";fi

3. pyenv versions
4. pyenv global <xxx_version>

brew install pyenv