How to fix “zsh: command not found: python” error? (macOS Monterey 12.3, python 3.10, Atom IDE, atom-python-run 0.9.7)

Anyone updating their macOS to Monterey 12.3 will find that they suddenly no longer have the system provided Python 2.

The reason for this is that Apple removed the system-provided python 2 installation (details).

So a workaround/solution for this is to use pyenv to install python 2.7 (or any other specific version you need).

1. Install pyenv with brew to manage different python versions: brew install pyenv
2. List all installable versions with pyenv install --list
3. Install python 2.7.18 with pyenv install 2.7.18
4. List installed versions with pyenv versions
5. Set global python version with pyenv global 2.7.18
6. Add eval "$(pyenv init --path)" to ~/.zprofile (or ~/.bash_profile or ~/.zshrc, whichever you need)
7. Relaunch the shell and check that python works.

OK, after a couple of days trying, this is what has worked for me:

1. I reinstalled Monterey (not sure it was essential, but I just figured I had messed with terminal and $PATH too much).
2. I installed python via brew rather than from the official website.
   It would still return command not found error.
3. I ran echo "alias python=/usr/bin/python3" >> ~/.zshrc in terminal to alias python with python3.

Problem solved.

As far as I get it, there is no more pre-installed python 2.x in macOS as of 12.3 hence the error. I still find it odd though that atom-python-run would call for python instead of python3 despite the settings.

If you simply installed python3 just use python3 as the command instead of just python. In my case I had to install pynev first via brew using brew install pyenv.

But still after using pynev to install python 2.7.18 and setting it as a global version using pyenv global 2.7.18 I still ran into an error while trying to run python.

What worked for me (since I already had python3 installed) is by changing my command to use python3 instead of just python. Of course, this won’t be a solution to everyone who may want to use python 2.

I got zsh: Command not found python after installing using https://www.python.org/ftp/python/3.10.4/python-3.10.4-macos11.pkg

I solved it by configuring the ENVIRONMENT. I added a line alias python=/usr/local/bin/python3.10 into the .zshrc.(you must be sure it is the true path！)

My macOS (Apple Silicon):

Darwin Johns-MacBook-Pro.local 21.4.0 Darwin Kernel Version 21.4.0: Mon Feb 21 20:35:58 PST 2022; root:xnu-8020.101.4~2/RELEASE_ARM64_T6000 arm64