mac 设置默认的python 关闭终端后再次打开仍是python3

1.打开终端，输入：vim ~/.bash_profile
2.在该文件添加：
alias python="/usr/local/bin/python3.X"
alias pip="/usr/local/bin/pip3.X"

3.重启终端，输入：source ~/.bash_profile

4.重启终端，输入：vim ~/.zshrc

5.在该文件添加：source ~/.bash_profile