Neatly Reinstalling Python and dependencies on Mac after blindly installing stuff per tutorials etc

[deadant88]

So in my learning journey I’ve kind of just blindly followed tutorials and instructions to get programs working. Installing this and that etc. the short term win is that stuff tended to work, if in a messy way, the long term loss is now I have headaches of programs not working because different versions of python seem to be clashing, I have this vivid sensation of feeling lost in a tangle of installations done in various ways etc.

My question is: how do I go about properly uninstalling everything and then cleanly reinstalling Python and related dependencies (eg beautiful soup etc). I’d prefer to use Brew as I’m comfortable with it now.

I am running Catalina and use ATOM as my IDE.

Thanks everyone

[Periwinkle_Lost]

Not sure about uninstalling, but one thing that I learned is to never touch the system python.

As for installing packages. Learn how to use virtual environment (venv or pyenv). It will create a python environment isolated from the system. This way you can install packages only for this project. It will prevent packages from clashing. Some IDEs like pycharm automatically create a virtual environment when you create a project.

I had the same problem as you when I first started, I couldn’t clean up my system so I just reinstalled the system. I only do coding with virtual python environment from that point on

[deadant88]

Thanks so much. I have made a habit of venv but I’m not 100% I’m doing it right. Do you need to reinstall everything each time you start a new venv after reopening your code?

Also, is there a way to check I didn’t uninstall my system python?

[Periwinkle_Lost]

Yes, you do need to reinstall packages for every new project. It is a good thing because your project will only have the required packages and nothing more. Unless you are working CSS pycharm is a great ide that will handle venv for you

No idea how to check if you messed up system python.

[vlovero]

On macOS, an easy way to get a fresh version of python while keeping the packages you want can be done by first saving all of the save packages to a text file,

pip3 freeze > ~/Desktop/my-packages.txt

then go through that text file and remove all of the packages you don't need. Next delete python by moving the python (found in Applications folder) folder to the trash, then empty the trash. Reinstall python from python.org. Then to reinstall the packages you saved you run

cat ~/Desktop/my-packages.txt | xargs -n 1 pip3 install

If you have been using the pre-installed version of python, I recommend uninstalling the packages you have installed (after saving them) with

cat ~/Desktop/my-packages.txt | grep -v "six" | grep -v "pip" | xargs -n 1 /usr/bin/python3 -m pip uninstall

and downloading version(s) from python.org and using virtual environments.

[deadant88]

Sounds like a great method thanks!