Reticulate fails automatic configuration in R package

Question

I'm working on a R package, that makes use of reticulate to call some functions of a Python package I implemented, installable through pip.

Following its documentation, I setup the reticulate automatic configuration of Python dependencies as follows, in the DESCRIPTION file of my package:

Config/reticulate:
  list(
    packages = list(
      list(package="my_python_package", pip=TRUE)
    )
  )

where my_python_package is the Python package I need to use.

If I install the package locally, where I have the required Python package already installed, everything works fine.
However, if I try to install and use the R package in an environment without the Python package already installed, I get the following error:

Error in py_module_import(module, convert = convert) : 
  ModuleNotFoundError: No module named 'my_python_package'

Detailed traceback:
  File "/home/runner/work/_temp/Library/reticulate/python/rpytools/loader.py", line 39, in _import_hook
    module = _import(

as if reticulate is not able to configure correctly the environment.

Also, the Python package should not be the problem, since when it is installed, I am able to import it and use its functions with no errors.

From the reticulate documentation it seems Config/reticulate: ... is all is needed, but maybe I am missing something.

Answer 1

I noticed this issue https://github.com/rstudio/reticulate/issues/997 on the reticulate GitHub repository. Apparently, the automatic configuration through Config/reticulate only works if a conda environment is already loaded.

Therefore, I think the only way to configure the correct environment is on the .onLoad function:

• check if Anaconda is installed, otherwhise launch the Miniconda installation through reticulate::install_miniconda()
• check if the environment is already present, otherwise create create it through reticulate::conda_create(envname),
• install the Python dependencies if necessary through reticulate::conda_install(envname, packages),
• load the configured environment.

In this way, the first time the package is loaded, the environment will be correctly created.
After that, the environment will be automatically loaded.