I would need to see what it contains first.
In a cmd could you type "echo %PYTHONPATH%" and post the result here.
It should look like what you could see in the notebook.
Here is an example of a environement file for windows:
@set HOMETEL=C:\opentelemac\trunk
@set USETELCFG=winHPC
@set SYSTELCFG=%HOMETEL%\configs\systel.edf.cfg
@set SOURCEFILE=%HOMETEL%\configs\pysource-win.bat
@set PATH=%HOMETEL%\scripts\python3;%PATH%
@set PYTHONPATH=%HOMETEL%\scripts\python3;%PYTHONPATH%
@set PYTHONPATH=%HOMETEL%\builds\%USETELCFG%\wrap_api\lib;%PYTHONPATH%
@set LD_LIBRARY_PATH=%HOMETEL%\builds\%USETELCFG%\wrap_api\lib;%LD_LIBRARY_PATH%