Shims

After installation Rye places two shims on your PATH: python and python3. These shims have specific behavior that changes depending on if they are used within a Rye managed project or outside.

Inside a Rye managed project they resolve to the Python interpreter of the virtualenv. This means that even if you do not enable the virtualenv, you can just run python in a shell, and it will automatically operate in the right environment.

Outside a Rye managed project it typically resolves to your system Python, though you can also opt to have it resolve to a Rye managed Python installation for you. This is done so that it's not disruptive to your existing workflows which might depend on the System python installation.

Global Shims

new in 0.9.0

To enable global shims, you need to enable the global-python flag in the config.toml file:

rye config --set-bool behavior.global-python=true

Afterwards if you run python outside of a Rye managed project it will spawn a Python interpreter that is shipped with Rye. It will honor the closest .python-version file for you. Additionally you can also explicitly request a specific Python version by adding +VERSION after the python command. For instance this runs a script with Python 3.8:

python +3.8 my-script.py

Note

Selecting a specific Python version this way only works outside of Rye managed projects. Within Rye managed projects, the version needs to be explicitly selected via .python-version or with the requires-python key in pyproject.toml.