How to run a module from another directory?

Question

I have a python 2.7.15 project (I know, legacy reasons) living on my computer and I can run different files as a module from there:

cd /home/me/code/project
python -m path.to.module

This works fine. The problem is I am invoking these modules from another program living in another directory. Supposedly this will work if I set the PYTHONPATH.

export PYTHONPATH=/home/me/code/project
cd /home/me/code/controller
python -m path.to.module

However, this fails with:

No module named path.to.module

This fails directly on the command line, so it has nothing to do with me invoking it from another program.

How do I invoke this module from another directory, if PYTHONPATH does not succeed?

• Nuno André: python -m expects the name of the module, not the path. If it's in your PYTHONPATH you should be able to run it with python -m module. python -m pip is a good example of this.
• TamaMcGlinn: @prismofeverything What workaround did you find?

Answer 1

The issue with PYTHONPATH is it changes sys.path, which is how the python interpreter searches for modules when importing modules. This is different than calling python to run a script. Unfortunately, I do not know a pythonic solution to this. One solution is to run a bash script that changes these directories for you:

Create a bash script called runModule.sh

#!/bin/sh
python -m some_module
cd path/to/other_module
python -m other_module

Make it executable

chmod -x ./runModule.sh

Then run it

./runModule.sh

• prismofeverything: Hi Ryan, thanks for the response! So you are saying that there is no way to run a module from another directory, without in some way cding into that directory? This seems so bad, but I guess is in line with all the other python environment pain and gotchas. I'll find some other way, thanks!
• Ryan: The issue here is that the path variables that python uses to search are from within a python instance. You are calling a module on the command line from another directory. I may not understand your problem, but you could also build a python script that imports this module and change the sys.path variable within that python script to location of the module.
• prismofeverything: Got it, that makes sense! I found a workaround, thanks for the insight.