I need to be able to switch back and forth between Python 2 and 3. How do I do that using Homebrew as I don't want to mess with path and get into trouble.
Right now I have 2.7 installed through Homebrew.
I would use pyenv You can install it:
$ brew install pyenv
Once you have it, you can install different versions of python and choose which one you can use. Example:
$ pyenv install 2.7.5
You can check the versions you have installed with:
$ pyenv versions
And you can switch between python versions with the command:
$ pyenv global 3.3.1
Also you can set a python version for the current directory with:
$ pyenv local 2.7.5