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/python@3.8/3.8.3_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.

score 155 · Accepted Answer · edited Jan 26 '23 at 17:26

155

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 (For a recent MacOS you may want to replace ~/.bash_profile with ~/.zshrc as that is the default shell)

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

eval pyenv path

eval "$(pyenv init --path)"

Verify your current python version the system is using

python3 --version

edited Jan 26 '23 at 17:26

Mihir Mehta

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answered Jul 14 '20 at 16:35

Shayan

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Also eval "$(pyenv init -)" to .bash_profile or .bashrc required. Then source .bashrc and reopened terminal is worked for me. – Almas Dusal Aug 20 '20 at 23:20
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For newbies, you might clarify that you need to either brew install or git clone (but not both) depending on whether you need the latest version. – C8H10N4O2 Dec 09 '20 at 15:53
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I just wanted to add that to finally set the pyenv global 3.7, you need to use the default macOS terminal. It doesn't work on the iTerm2. – AnupamChugh Dec 29 '20 at 10:36
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@almas Dusal, can you be a bit more explicit what you mean by eval .... to ... using maybe command?.... got it it means add ```eval "$(pyenv init -)"``` to the .zshrc or .bashrc file – soMuchToLearnAndShare Jan 12 '21 at 15:23
@Shayan it would be nice if you could add the pyenv init part into the answer. – soMuchToLearnAndShare Jan 12 '21 at 15:33
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Failing on M1 chip – Dr. Freddy Dimethyltryptamine Apr 17 '21 at 20:08
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I did all you suggested to downgrade from 3.9 to 3.8, but at the end python3 --version gives me python 3.9 – Mehdi Abbassi May 10 '21 at 06:22
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I had to also do this for pyenv to work to downgrade from 3.9 to 3.7 https://github.com/pyenv/pyenv/issues/849#issuecomment-863456765 – Micah.Fay Aug 09 '21 at 21:27
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I had to add `eval "$(pyenv init --path)"` in order to work – Hristo Todorov Oct 23 '21 at 14:41
`eval "$(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 "$(pyenv init --path)"` – soMuchToLearnAndShare Dec 01 '21 at 12:16
if you happen to have SDKMAN installed, be sure your command like below is not overriding or setting to a wrong path `export PATH="/usr/local/opt/python@3.8/bin:$PATH"` – soMuchToLearnAndShare Dec 01 '21 at 12:21
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Thank you so much! for macOS Monterey replace ~/.bash_profile with ~/.zshrc – Amitkumar Karnik Jul 15 '22 at 05:09
THIS IS GREAT!!! Just need to make sure eval ```"$(pyenv init --path)" ``` runs on terminal init – Talita Mar 28 '23 at 06:15

score 16 · Answer 2 · answered Jul 14 '20 at 15:55

16

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

answered Jul 14 '20 at 15:55

Nicolas Acosta

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Great solution, on MacOS I had to use '3.7.13' for this to work. '3.7' was no joy. – Waxhaw Jul 07 '22 at 12:45

score 4 · Answer 3 · answered Oct 29 '20 at 23:54

brew only approach.

rm -rf $(brew --repository)/Library/Taps/company
brew tap-new company/team
brew extract python@3.7 company/team  --version=3.7.9 
HOMEBREW_NO_AUTO_UPDATE=1  brew install company/team/python@3.7.9
brew link --force company/team/python@3.7.9

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

Cagri Yonca · Answer 4 · 2021-11-03T06:51:07.750

-1

Reinstalled xcode-select (used solution here)
Downgraded python 3.9 to 3.8.12 (used @Shayan's solution here)
Restarted terminal and checked default Python version, that's all

This is my solution for M1 Mac

edited Nov 03 '21 at 06:51

answered Nov 02 '21 at 23:02

Cagri Yonca

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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. – Gino Mempin Nov 03 '21 at 01:25
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. – PCM Nov 03 '21 at 03:39
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 May 04 '22 at 07:20
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 https://stackoverflow.com/a/69378384/2860309 and add `eval "$(pyenv init --path)"` into the `.zshrc` file. – therightstuff May 04 '22 at 07:28

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

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