The environment variable PYTHONPATH is actually only added to the list of locations Python searches for modules. You can print out the full list in the terminal like this:

python -c "import sys; print(sys.path)"

Or if want the output in the UNIX directory list style (separated by :) you can do this:

python -c "import sys; print(':'.join(x for x in sys.path if x))"

Which will output something like this:

/usr/local/lib/python2.7/dist-packages/feedparser-5.1.3-py2.7.egg:/usr/local/lib/
python2.7/dist-packages/stripogram-1.5-py2.7.egg:/home/qiime/lib:/home/debian:/us
r/lib/python2.7:/usr/lib/python2.7/plat-linux2:/usr/lib/python2.7/lib-tk:/usr/lib
/python2.7/lib-old:/usr/lib/python2.7/lib- dynload:/usr/local/lib/python2.7/dist-
packages:/usr/lib/python2.7/dist-packages:/usr/lib/python2.7/dist-packages/PIL:/u
sr/lib/python2.7/dist-packages/gst-0.10:/usr/lib/python2.7/dist-packages/gtk-2.0:
/usr/lib/pymodules/python2.7

PATH variable defines the directories which are searched when executing commands. However when you execute python sleep_plotter.py 113testCtM113.txt, sleep_plotter.py is an argument to the python program (command). Shell uses PATH to find python, but not its arguments.

You can add an executable attribute to your script:

$ chmod +x /Users/myname/python_functions/bin/sleep_plotter.py

Add a shebang sequence to the top (first line) of your Python script:

#!/usr/bin/env python

And run the script directly as a command:

$ sleep_plotter.py 113testCtM113.txt

sys.path in Python is a "list of strings that specifies the search path for modules. Initialized from the environment variable PYTHONPATH, plus an installation-dependent default." (taken from the Python online documentation).

For sys.path to be affected by PYTHONPATH, the latter has to be an environment variable. If it's not an environment variable but just a shell variable, it will not be visible by the python interpreter. You turn it into an environment variable by exporting it after setting its value, or at the same time, as in

export PYTHONPATH=/some/path:/goes/here

Typically, the environment variable $PYTHONPATH is empty (try echo $PYTHONPATH). The actual list of folders python searches for libraries can be found with (in python):

import sys
print(sys.path)

This will consist (in search order) of the current directory, any directories in your $PYTHONPATH, and finally the default library directories, set by site.py. The main default locations are (where X.Y is the python version, eg 2.7):

/usr/lib/pythonX.Y (python system libraries, eg re, urllib)
/usr/lib/pythonX.Y/dist-packages (python libraries installed with deb packages)

If you use pip install --user or similar to install libraries as yourself, it will also contain the user library directory:

/home/USERNAME/.local/lib/pythonX.Y/site-packages

You can manipulate the PYTHONPATH by either setting the environment variable before you launch python (PYTHONPATH=$PYTHONPATH:/foo/bar), or by editing sys.path once you've started python (import sys; sys.path = ["/foo/bar"] + sys.path).

However, if you want to play with your own python libraries, a good idea is to create a virtualenv. This is a directory in which you can play around with your own versions of python libraries without any risk of messing up the python libraries used by the system. See How to set up and use a virtual python environment in Ubuntu? for information about creating and using a virtualenv.

When you add to PYTHONPATHS on two lines, set is handling it & it knows that there are two Items : this will work.

When you add to PYTHONPATHS on one line, you have included a space, set is handling it but it will not alter the given single Item & you end up with one Item having a space : not going to work.

All variables in fish are lists : "Multi-line" way gives you 1 variable with 2 items in the list while the "Single-line" way gives you 1 variable with 1 item in the list where this 1 item has a space.

When echo comes along : In one case, it shows a space between the "Multiple Items", & In the other case, it shows the space in the "Single Item" : All this is normal.

You know what has worked for me really well on windows.

My Computer > Properties > Advanced System Settings > Environment Variables >

Just add the path as C:\Python27 (or wherever you installed python)

OR

Then under system variables I create a new Variable called PythonPath. In this variable I have C:\Python27\Lib;C:\Python27\DLLs;C:\Python27\Lib\lib-tk;C:\other-folders-on-the-path

This is the best way that has worked for me which I hadn't found in any of the docs offered.

EDIT: For those who are not able to get it, Please add

C:\Python27;

along with it. Else it will never work.

command: echo “::add-path::/path/to/dir” will pepend a directory to the system PATH variable for all subsequent actions in the current job. But look at your code, are you searching ‘set-env’?

echo "::set-env name=PYTHONPATH::home/runner/work/"