gmic-py prints exception on display-less system even without display command being invoked

[robin-pfeiffer]

When running the following G'MIC commands on a display-less system (WSL Ubuntu 20.04), gmic-py (2.9.2 from PyPI) still prints a message out about not being able to display images because of missing matplotlib or ipython dependencies

import gmic; gmic.run("sp lena blur 10 output lena.png")

Outputs

gmic-py: Working in display-less mode.
gmic.GmicException: Could not use matplotlib neither ipython to try to display images

[robin-pfeiffer]

Maybe a setting to run G'MIC in a silent mode would be an option to pass to a G'MIC instance when creating one. That way, the stdout and stderr don't get polluted. I don't know if this is already possible, but I couldn't find anything in the documentation of gmic-py. Something like this would be helpful:

import gmic

gmicInstance = gmic.Gmic(silent=True)

As a temporary fix, I redirect both stdout for the display-less mode message and stderr for the dependencies' error while executing G'MIC commands like so:

import gmic
import contextlib
import io

f = io.StringIO()
with contextlib.redirect_stderr(f):
    with contextlib.redirect_stdout(f):
        gmic.run("sp lena blur 10 output lena.png")