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I've recently installed both Pyenv and Poetry and want to create a new Python 3.8 project. I've set both the global and local versions of python to 3.8.1 using the appropriate Pyenv commands (pyenv global 3.8.1 for example). When I run pyenv version in my terminal the output is 3.8.1. as expected.

Now, the problem is that when I create a new python project with Poetry (poetry new my-project), the generated pyproject.toml file creates a project with python 2.7:

[tool.poetry]
name = "my-project"
version = "0.1.0"
description = ""
authors = ["user <user@email.com>"]

[tool.poetry.dependencies]
python = "^2.7"

[tool.poetry.dev-dependencies]
pytest = "^4.6"

[build-system]
requires = ["poetry>=0.12"]
build-backend = "poetry.masonry.api"

It seems that Poetry defaults back to the system version of Python. How do I change this so that it uses the version installed with Pyenv?

Edit

I'm using MacOS, which comes bundled with Python 2.7. I think that might be causing some of the issues here. I've reinstalled Python 3.8 again with Pyenv, but when I hit Poetry install I get the following error:

The currently activated Python version 2.7.16 is not supported by the project (^3.8).
Trying to find and use a compatible version.

[NoCompatiblePythonVersionFound]
Poetry was unable to find a compatible version. If you have one, you can explicitly use it via the "env use" command.

Should I create an environment explicitly for the project using Pyenv or should the project be able to access the correct Python version after running pyenv local 3.8.1.? When I do the latter, nothing changes and I still get the same errors.

P4nd4b0b3r1n0
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  • Does [this issue](https://github.com/python-poetry/poetry/issues/172) help you / clarify the status? – a_guest Jan 19 '20 at 13:45

14 Answers14

34

Alright, I figured the problem. A little embarrassingly, I had not run pyenv shell 3.8.1 before running any of the other commands. Everything works now. Thank you all for your efforts.

P4nd4b0b3r1n0
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    Interestingly, I needed to do this, even though I had a `.python-version` with the correct version in the directory. – Matthew Schinckel Mar 01 '21 at 23:00
  • If the `.python-version` is not being read, you might need to fix your `pyenv` configuration: https://github.com/pyenv/pyenv#basic-github-checkout – juanmirocks Nov 02 '21 at 17:22
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    This is the solution to most of the problems I have. (And embarrassingly, I need to google this answer every time I do this!) Thank you. – Joe Sadoski Jan 23 '22 at 22:47
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    @juanmirocks that was exactly the issue in my case - I re-configured `pyenv` to use the updated logic and `.python-version` is now discovered properly by `poetry`: `Upgrade note: The startup logic and instructions have been updated for simplicity in 2.3.0. The previous, more complicated configuration scheme for 2.0.0-2.2.5 still works.` – jaklan Aug 03 '22 at 16:05
32

pyproject.toml is used to define all the dependencies for your project, including the supported python version.

The line your complaining about is just saying that the versions of python supported by the project is python2.7 or greater, this is independent of what versions of python you've installed with pyenv.

python = "^2.7"

If you want to update the versions of python supported by the project you can edit the file directly and run poetry update.

If you want to use multiple versions of python you need to make sure poetry is using the correct dependencies for the version of python you are using. To change the specific version poetry is using you should use poetry env,

  • poetry env list show the versions of python poetry can use
  • poetry env use <python> switches poetry to use that version.

For instance on my machine poetry has 3 virtual environments installed and is using the one associated with python3.6:

↪ poetry env list
sipy-a9sqc5pb-py3.6 (Activated)
sipy-a9sqc5pb-py3.7
sipy-a9sqc5pb-py3.8

I'm not sure how these virtual environments with interact with the shivs used by pyenv but their docs have a section relating to it

Managing Virtual Environments

There is a pyenv plugin named pyenv-virtualenv which comes with various features to help pyenv users to manage virtual environments created by virtualenv or Anaconda. Because the activate script of those virtual environments are relying on mutating $PATH variable of user's interactive shell, it will intercept pyenv's shim style command execution hooks. We'd recommend to install pyenv-virtualenv as well if you have some plan to play with those virtual environments.

Community
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Sam Broster
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    "Poetry should manage all your python dependencies so that there is no need to use pyenv."—pyenv isn't for _dependencies_. It manages versions of _Python itself_. Does Poetry do that natively? – ChrisGPT was on strike Jan 19 '20 at 13:48
  • Ah my mistake. The keypoint is that the `pyproject.toml` file is saying that your project supports python2.7 or great, it is not saying 'I want to use python3.8'. If you want to update the versions of python your project supports then update toml file directly – Sam Broster Jan 19 '20 at 13:55
  • I've updated my answer, hopefully it makes more sense now. – Sam Broster Jan 19 '20 at 14:06
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    Great answer, thanks. Although I do have a follow-up question: How do I increase the number of virtual environment options for Poetry? When I run `poetry env list` now, there's only one option and that's for Python 2.7. What I'd like then is to also have and option for Python 3.8 for example. – P4nd4b0b3r1n0 Jan 19 '20 at 14:17
  • I think you want something like: `poetry use python3.8` to switch to 3.8, and then `poetry install` to create the virtual env for 3.8 – Sam Broster Jan 19 '20 at 14:21
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    I have no idea if the command changed over the last year, but I think the current command is `poetry env use python3.8` . Source: https://web.archive.org/web/20210130151158/https://python-poetry.org/docs/managing-environments/ – blong Mar 09 '21 at 20:49
  • `poetry env use` fixed my problem. Haven't dug into details yet, but I'm guessing I initially created the poetry env (via `poetry install`) with 3.10, then added a .python-version for 3.11, but poetry remembered creating the venv using 3.10, and complained about the mismatch. – odigity Jun 21 '23 at 16:02
31

you can specify an explicit python executable for poetry using

poetry env use <path to python executable>

This worked for me.

Jan
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    The other answers didn't work for me, but this one did. `poetry` is such a moving target (argh...) that I suspect the others ones are obsolete. This one deserves to be pushed to the top. – Zephaniah Grunschlag Feb 10 '23 at 20:08
  • Worked for me on Windows with multiple versions of Python installed. Just put the path in quotes and point it to whichever version you want. – Rishi Latchmepersad Apr 20 '23 at 13:37
20

My solution to this.

First of all see the situation with this command

poetry env list

If you have an output like this: project_name-QI_LjVaV-py3.9 (Activated)

you may want to get rid of this env.

So you do the "deactivation" first:

deactivate

and then the "remove" after :

poetry env remove project_name-QI_LjVaV-py3.9

Now the same command:

poetry env list

should return nothing.

Then you do:

which python3

and, if the version is ok, you use this same exact output of the path of python, to tell to poetry (Example):

poetry env use /usr/bin/python3

Do again

poetry env info

to be sure that is using the version of the python you want.

You can continue with

poetry install
RobyB
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    Thanks! This solved the issue for me after trying many other solutions for an hour. I think removing the created env was key. – SaTa Mar 10 '23 at 12:43
13

On my machine I was able to fix the "currently activated Python version is not supported by the project" error by reinstalling Poetry:

curl -sSL https://install.python-poetry.org | python3 - --uninstall
curl -sSL https://install.python-poetry.org | python3 -

After that,poetry was able to find the correct version installed by pyenv.

Jace Browning
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4

In my case, I had to delete and recreate the virtualenv used by poetry. This is because I added the python version restrictions (e.g. python = ">=3.6.2 <3.7") after creating the virtualenv.

Steps

  • Delete the original one: run poetry env remove myApp-XkghI9p6-py3.6
  • Run any poetry step, to create it, or run poetry shell, and confirm poetry run python --version is the correct version.
Ben Butterworth
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1

in my case i was running poetry via python version installed in homebrew but i tried to connect it to pyenv's python version. (since it is installed via pip i guess....)

I detected it by running:

$ where poetry

$ /opt/homebrew/bin/poetry

what worked is to remove it and install poetry again via pip in the desired version and use it the same way:

pyenv shell python3.11
python -m pip install poetry
python -m poetry install
adir abargil
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0

Even though this issue has been resolved, I am writing this for somebody who comes across this problem again. After all attempts my python -V always resulted in 2.7 and no discussions mentioned running pyenv shell (surprising to me!) Adding pyenv to path

$ echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n eval "$(pyenv init -)"\nfi' >> ~/.bash_profile

In my case I had to add it to .bashrc and not bash_profile. https://ggkbase-help.berkeley.edu/how-to/install-pyenv/

Worked!

Arpana Mehta
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In my case, the environment was messed up in some way that poetry failed to activate the virtualenv properly.

Try using a different shell: perhaps, sh, or zsh. If everything works in that shell, this proves that your environment is as messed up as mine was :)

Use this command in both shells:

$ env

and try to spot the difference

kolypto
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You can remove the python version from pyproject.toml file and then run Poetry install

Reza.Razi
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What worked for me was to run python3.8 -m poetry install.

Chiel
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First I manually modified pyproject.toml and set

[tool.poetry.dependencies]
python = "^3.11.4"

Later in CLI

To deactivate the virtual env:

exit

To remove the virtual env

# rm -rf <path_to_virtual_env> 
# in my case:
rm -rf .venv

To set the local Python version (sets .python-version file)

pyenv local 3.11.4

To change Poetry env's Python version (TBH this might be the only command you need):

poetry env use 3.11.4

To activate a new virtual env:

poetry shell

And you should be all good to go. Check Python version with:

python -V
Bartłomiej Skwira
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For anyone not using the venv and came looking for the answer on making poetry use specific version of python : Upgrade pip to latest version python3.x -m pip install --upgrade pip and then install poetry for that python version python3.x -m pip install poetry

raghavd
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try re-installing poetry again

pip uninstall poetry
pip install poetry
Mike Szyndel
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Paromita Sengupta
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