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Installing the latest version of Python on Mac OS Catalina and overriding the old default pre-installed version

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Installing the latest version of Python on Mac OS Catalina and overriding
the old default pre-installed version
Photo by David Clode on Unsplash

I finally did it. I successfully installed Python version 3.7.7 via Homebrew on my Mac laptop with OS Catalina installed.

For those of you that still might be trying to figure out how to do this, I will walk you through.

The reason why I was eager to make sure that I had the latest version installed was because I am working on publishing (open-source) teaching-related documentation on Read The Docs, and I need to have Python installed in order to be able to install the programs necessary to publish there.

The default 2.7.17 version of Python was retired this past January 2020. I had tried back then to replace it with Python 3+, but was unsuccessful at the time. The following is what I did today:

First I updated Homebrew. Yes, I used Homebrew to (re)install Python. It's really easy. It's just a matter of putting the pieces of the puzzle together correctly!

I ran the command

brew update

To update Homebrew. Then I ran the command

brew install python

To (re)install Python. Then I ran

python --version

To see which version of Python my Mac laptop was recognizing. It still recognized only Python 2.7.17. So I ran the following command:

brew info python

It told me the path to my newly installed Python 3.7.7. I had to change the path to Python in order for my Mac to recognize the newly installed version. This is what the command brew info python returned to me in Terminal:

Python has been installed as
Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to
`python3`, `python3-config`, `pip3` etc., respectively, have been installed into

So I had to add the following at the bottom of my .zshrc file to update the path to my newly installed version of Python via Homebrew:

export PATH=/usr/local/opt/python/libexec/bin:$PATH

Then I made sure to quit Terminal and go back in so that the path would actually be updated in a new Terminal window instance.

Then I checked what version of Python was recognized now with

python --version

And this is what was returned:

Python 3.7.7

Success! It's as easy as that.

And BTW, if you don't know how to access your .zshrc file in Catalina, you simply execute the following command:

open .zshrc

And your file will open in a new window. Then you can paste

export PATH=/usr/local/opt/python/libexec/bin:$PATH

At the bottom of the file.

I will be embedding this episode of Plugging in The Holes along with a transcript in the form of a post on for your hearing and reading pleasure. Bye for now!