title: "Using Python with renv"

output: rmarkdown::html_vignette

vignette: >

```{r, include=FALSE}

If you're using renv with an R project that also depends on some Python

packages (say, through the [reticulate](https://rstudio.github.io/reticulate/)

package), then you may find renv's Python integration useful.

Python integration can be activated on a project-by-project basis. Use

`renv::use_python()` to tell renv to create and use a project-local Python

environment with your project. If the reticulate package is installed and

active, then renv will use the same version of Python that reticulate

normally would when generating the virtual environment. Alternatively, you can

set the `RETICULATE_PYTHON` environment variable to instruct renv to use a

different version of Python.

If you'd rather tell renv to use an existing Python virtual environment, you

can do so by passing the path of that virtual environment instead -- use

`renv::use_python(python = "/path/to/python")` and renv will record and

use that Python interpreter with your project. This can also be used with

pre-existing virtual environments and Conda environments.

If you'd like to deactivate Python integration for a project, you can do so

with:

This removes the `Python` section from `renv.lock`. Note that this does not

remove any previously-created virtual environments or `requirements.txt` files;

those can be deleted manually if no longer needed.

Once Python integration is active, renv will attempt to manage the state of

your Python virtual environment when `snapshot()` / `restore()` is called. With

this, projects that use renv and Python can ensure that Python dependencies

are tracked in addition to R package dependencies. Note that future restores

will require both `renv.lock` (for R package dependencies) and

`requirements.txt` (for Python package dependencies).

When using virtual environments, the following extensions are provided:

- `renv::snapshot()` calls `pip freeze > requirements.txt` to save the

set of installed Python packages;

- `renv::restore()` calls `pip install -r requirements.txt` to install

the previously-recorded set of Python packages.

When using Conda environments, the following extensions are provided:

- `renv::snapshot()` calls `conda env export > environment.yml` to save the

set of installed Python packages;

- `renv::restore()` calls `conda env [create/update] --file environment.yml` to

install the previously-recorded set of Python packages.