Poetry makes project environment isolation one of its core features.
What this means is that it will always work isolated from your global Python installation. To achieve this, it will first check if it's currently running inside a virtual environment. If it is, it will use it directly without creating a new one. But if it's not, it will use one that it has already created or create a brand new one for you.
By default, Poetry will try to use the currently activated Python version to create the virtual environment for the current project.
However, for various reasons, this Python version might not be compatible
python requirement of the project. In this case, Poetry will try
to find one that is and use it. If it's unable to do so then you will be prompted
to activate one explicitly, see Switching environments.
To easily switch between Python versions, it is recommended to use pyenv or similar tools.
For instance, if your project is Python 2.7 only, a standard workflow would be:
pyenv install 2.7.15 pyenv local 2.7.15 # Activate Python 2.7 for the current project poetry install
Sometimes this might not be feasible for your system, especially Windows where
is not available, or you simply prefer to have a more explicit control over your environment.
For this specific purpose, you can use the
env use command to tell Poetry
which Python version to use for the current project.
poetry env use /full/path/to/python
If you have the python executable in your
PATH you can use it:
poetry env use python3.7
You can even just use the minor Python version in this case:
poetry env use 3.7
If you want to disable the explicitly activated virtual environment, you can use the
system Python version to retrieve the default behavior:
poetry env use system
If you want to get basic information about the currently activated virtual environment,
you can use the
env info command:
poetry env info
will output something similar to this:
Virtual environment Python: 3.7.1 Implementation: CPython Path: /path/to/poetry/cache/virtualenvs/test-O3eWbxRl-py3.7 Valid: True System Platform: darwin OS: posix Python: /path/to/main/python
If you only want to know the path to the virtual environment, you can pass the
poetry env info --path
You can also list all the virtual environments associated with the current project
env list command:
poetry env list
will output something like the following:
test-O3eWbxRl-py2.7 test-O3eWbxRl-py3.6 test-O3eWbxRl-py3.7 (Activated)
Finally, you can delete existing virtual environments by using
poetry env remove /full/path/to/python poetry env remove python3.7 poetry env remove 3.7 poetry env remove test-O3eWbxRl-py3.7
If you remove the currently activated virtual environment, it will be automatically deactivated.