Could not import matplotlib.pyplot, - Nevergrad Issue

[Michaelmlewis]

I am trying to install nevergrad via pip
using the following
library("reticulate") virtualenv_create("r-reticulate") use_virtualenv("r-reticulate", required = TRUE) Sys.setenv(RETICULATE_PYTHON = "C:/Users/MIAT40093/Documents/.virtualenvs/r-reticulate/Scripts/python.exe") py_install("numpy", pip = TRUE) py_install("nevergrad", pip = TRUE)

when I run py_module_available("nevergrad") I get the following error
C:\Users\MIAT401\DOCUME1\VIRTUA1\R-RETI1\Lib\site-packages\cma\s.py:13: UserWarning: Could not import matplotlib.pyplot, therefore cma.plot() etc. is not available
_warnings.warn('Could not import matplotlib.pyplot, therefore'
[1] FALSE

Here is my 'py_config() '
python: C:/Users/MIAT40093/Documents/.virtualenvs/r-reticulate/Scripts/python.exe
libpython: C:/Users/MIAT40093/AppData/Local/Programs/Python/Python311/python311.dll
pythonhome: C:/Users/MIAT40093/Documents/.virtualenvs/r-reticulate
version: 3.11.5 (tags/v3.11.5:cce6ba9, Aug 24 2023, 14:38:34) [MSC v.1936 64 bit (AMD64)]
Architecture: 64bit
numpy: C:/Users/MIAT40093/Documents/.virtualenvs/r-reticulate/Lib/site-packages/numpy
numpy_version: 1.26.0

NOTE: Python version was forced by RETICULATE_PYTHON

I tried alot of the mentioned solutions, with no luck :(

Would you please advise

[gufengzhou]

Very tricky issue :( reticulate often fails to pick up the right python config by default. Below is my py_config(), as you see I'm using the python libs installed by miniconda.

Maybe it's worth trying this out, in the documentation ?reticulate::install_python, you can see the "recommended" Python installation. Just to copy paste the content for easier reference here. I suggest NOT using the latest Python version because I remember reticulate having problems with the latest sometimes.

# In general, it is recommended that Python virtual environments are created using the copies of Python installed by  install_python(). For example:

library(reticulate)
version <- "3.9.12"
install_python(version)
virtualenv_create("my-environment", version = version)
use_virtualenv("my-environment")

# There is also support for a ":latest" suffix to select the latest patch release
install_python("3.9:latest") # install latest patch available at python.org

# select the latest 3.9.* patch installed locally
virtualenv_create("my-environment", version = "3.9:latest")
# Note
# On macOS and Linux this will build Python from sources, which may take a few minutes. Installation will be faster if some build dependencies are preinstalled. See https://github.com/pyenv/pyenv/wiki#suggested-build-environment for example commands you can run to pre-install system dependencies (requires administrator privileges). Python is built with PYTHON_CONFIGURE_OPTS=--enable-shared set.

# On Windows, prebuilt installers from https://www.python.org/ are used.