How to downgrade python version from 3.8 to 3.7 (mac)

Question

I'm using Python & okta-aws tools and in order to fetch correct credentials on aws I need to run okta-aws init. But got an error message of Could not read roles from Okta and the system prompted that"Your Pipfile requires python_version 3.7, but you are using 3.8.3 (/usr/local/Cellar/o/1.1.4/l/.venv/bin/python).

I've tried to search all the Pipfiles on the mac and it seems that the Pipflie under my ~/Pipfile and /usr/local/Cellar/[email protected]/3.8.3_2/libexec/bin/Pipfile all have the same python version of 3.8, while the Pipfile under my /usr/local/Cellar/okta-aws-tools/1.1.4/libexec/Pipfile has required python_version = 3.7.

I've been struggling with this for a while and really not sure how I can fix this.

Solution 1

Consider installing pyenv with Homebrew on macOS

brew update
brew install pyenv

OR Clone the repository to get the latest version of pyenv

 git clone https://github.com/pyenv/pyenv.git ~/.pyenv

Define your environment variables

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
source ~/.bash_profile

Restart your shell so the path changes take effect

exec "$SHELL"

Verify the installation and check the available python versions

pyenv install --list

Install the required python version

pyenv install 3.7

Set it as your global version after installation

pyenv global 3.7

Verify your current python version the system is using

python3 --version

Solution 2

I recommend you to install and use pyenv, a Python Version Management. Once intalled pyenv, install python 3.7:

pyenv install 3.7

And then set the environment PYENV_VERSION to version of python you want to use, on this case will be 3.7:

pyenv shell 3.7

Solution 3

brew only approach.

rm -rf $(brew --repository)/Library/Taps/company
brew tap-new company/team
brew extract [email protected] company/team  --version=3.7.9 
HOMEBREW_NO_AUTO_UPDATE=1  brew install company/team/[email protected]
brew link --force company/team/[email protected]

This creates a local tap, extracts python 3.7.X to a formula in that local tap and then installs and links that formula

The created local tap and the new formula file can be found in $(brew --repository)/Library/Taps/company/homebrew-team

Comments

[Almas Dusal]

Also eval "$(pyenv init -)" to .bash_profile or .bashrc required. Then source .bashrc and reopened terminal is worked for me.

[C8H10N4O2]

For newbies, you might clarify that you need to either brew install or git clone (but not both) depending on whether you need the latest version.

[AnupamChugh]

I just wanted to add that to finally set the pyenv global 3.7, you need to use the default macOS terminal. It doesn't work on the iTerm2.

[soMuchToLearnAndShare]

@almas Dusal, can you be a bit more explicit what you mean by eval .... to ... using maybe command?.... got it it means add eval "$(pyenv init -)" to the .zshrc or .bashrc file

[soMuchToLearnAndShare]

@Shayan it would be nice if you could add the pyenv init part into the answer.

[Dr. Freddy Dimethyltryptamine]

Failing on M1 chip

[Mehdi Abbassi]

I did all you suggested to downgrade from 3.9 to 3.8, but at the end python3 --version gives me python 3.9

[Micah.Fay]

I had to also do this for pyenv to work to downgrade from 3.9 to 3.7 github.com/pyenv/pyenv/issues/849#issuecomment-863456765

[Hristo Todorov]

I had to add eval "$(pyenv init --path)" in order to work

[Gino Mempin]

How exactly did you "Downgraded python 3.9 to 3.8.12" and set it "as global"? Because that was the exact question, the OP was struggling to downgrade the Python used in the project from 3.8 to 3.7. So a more detailed set of steps would be useful.

[PCM]

While this code may answer the question, providing additional context regarding why and/or how this code answers the question improves its long-term value.

[soMuchToLearnAndShare]

eval "$(pyenv init -)" used to work for me, and for somereason our IT installed some stuff on my mac os, now i have to use eval "$(pyenv init --path)"

[soMuchToLearnAndShare]

if you happen to have SDKMAN installed, be sure your command like below is not overriding or setting to a wrong path export PATH="/usr/local/opt/[email protected]/bin:$PATH"

[therightstuff]

Did you need to reinstall xcode-select in order for @Shayan's solution to work? If so, any idea why? I'm on an M1 Mac and the default Python version isn't updated even though both pyenv's global and shell versions are set correctly after restarting the terminal.

[therightstuff]

I don't see how reinstalling xcode-select is relevant (I'm using an M1 Mac and it was already installed), but the only addition I have to @Shayan's solution to make it work is to follow stackoverflow.com/a/69378384/2860309 and add eval "$(pyenv init --path)" into the .zshrc file.