Python - add PYTHONPATH during command line module run

 import sys
 sys.path.append('your certain directory')

Basically sys.path is a list with all the search paths for python modules. It is initialized by the interpreter. The content of PYTHONPATH is automatically added to the end of that list.

If you are running the command from a POSIX-compliant shell, like bash, you can set the environment variable like this:

PYTHONPATH="/path/to" python somescript.py somecommand

If it's all on one line, the PYTHONPATH environment value applies only to that one command.

$ echo $PYTHONPATH

$ python -c 'import sys;print("/tmp/pydir" in sys.path)'
False
$ PYTHONPATH=/tmp/pydir python -c 'import sys;print("/tmp/pydir" in sys.path)'
True
$ echo $PYTHONPATH

For Mac/Linux;

PYTHONPATH=/foo/bar/baz python somescript.py somecommand

For Windows, setup a wrapper pythonpath.bat;

@ECHO OFF
setlocal
set PYTHONPATH=%1
python %2 %3
endlocal

and call pythonpath.bat script file like;

pythonpath.bat /foo/bar/baz somescript.py somecommand

You may try this to execute a function inside your script

python -c "import sys; sys.path.append('/your/script/path'); import yourscript; yourscript.yourfunction()"