How to default Python3.8 on my Mac using Homebrew?

Question

I have updated my python 3 to the latest version 3.8:

brew search python ==> Formulae app-engine-python   gst-python          python ✔            [email protected] ✔ boost-python        ipython             python-markdown     wxpython boost-python3       micropython         python-yq  ==> Casks awips-python               kk7ds-python-runtime       mysql-connector-python  

But when I check the python3 version on my mac it still shows 3.7:

python3 --version  Python 3.7.6  

how can I default python3 to the latest 3.8 version using Homebrew ?

Edit: When I tried to use brew switch, it tells me I only installed python 3.7.6, but with last brew upgrade I'm pretty sure that python3.8.1 is installed with Homebrew

brew switch python 3.8.1 python does not have a version "3.8.1" in the Cellar. python's installed versions: 3.7.6_1 

Answer 1

Here is the solution:

If existing symlinks belong to python 3.7 you should unlink them:
brew unlink python

Basically all you need to do:
brew link --force [email protected]

OR force the link and overwrite all conflicting files:
brew link --force --overwrite [email protected]

OR if needed list all files that would be deleted:
brew link --overwrite --dry-run [email protected]

Thus you can switch to any python version available in the Homebrew repo.

Also check out this answer for pyenv usage

Answer 2

Ok, thanks to @gromgit from Homebrew community discussion (https://discourse.brew.sh/t/how-to-default-python-3-8-on-my-mac-using-homebrew/7050)

Here is the solution:

$ brew info [email protected] [email protected]: stable 3.8.1 (bottled) [keg-only] ... ==> Caveats Python has been installed as   /usr/local/opt/[email protected]/bin/python3 ... [email protected] is keg-only, which means it was not symlinked into /usr/local, because this is an alternate version of another formula.  If you need to have [email protected] first in your PATH run:   echo 'export PATH="/usr/local/opt/[email protected]/bin:$PATH"' >> ~/.bash_profile  For compilers to find [email protected] you may need to set:   export LDFLAGS="-L/usr/local/opt/[email protected]/lib"  For pkg-config to find [email protected] you may need to set:   export PKG_CONFIG_PATH="/usr/local/opt/[email protected]/lib/pkgconfig" 

I will stick to python (v3.7.6) at this time and wait for seamless upgrade of v3.8.1 in the future releases.