ImportError: No module named bs4 when called from launchd

Question

I am running the following python imports in a script that works fine from the command line in terminal and from the ipython notebook.

#!/usr/bin/python
import os
import re
import urllib
import urllib2 as ul
import sys
from bs4 import BeautifulSoup as bs

When it's called from a .plist file via Mac launchd I get the following error:

11/24/15 1:17:05 PM com.jerry.sat_images[668]   Traceback (most recent call last):
11/24/15 1:17:05 PM com.jerry.sat_images[668]     File "/Users/jerrykallam/python_practice/sat_image.py", line 6, in <module>
11/24/15 1:17:05 PM com.jerry.sat_images[668]       import bs4
11/24/15 1:17:05 PM com.jerry.sat_images[668]   ImportError: No module named bs4
11/24/15 1:17:05 PM com.apple.launchd.peruser.501[165]  (com.jerry.sat_images[668]) Exited with exit code: 1

From the command line and ipython bs4 imports and the script works fine. This is the .plist code that seems to work correctly. Not sure why the script fails to import bs4 only when called by launchd.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>Label</key>
        <string>com.jerry.satimages</string>
        <key>ProgramArguments</key>
        <array>
           <string>python</string>
            <string>/Users/jerrykallam/python_practice/sat_image.py</string>
        </array>
        <key>StartInterval</key>
        <integer>360</integer>
        <key>RunAtLoad</key>
        <true/>
    </dict>
</plist> 

Answer 1

This is likely because launchd runs its daemons as root, and bs4 is likely not installed in a location in the super user's PYTHONPATH. To fix this, you can add an EnvironmentVariables key, and set the value of your PYTHONPATH there. To figure out what your PYTHONPATH is, you can run echo $PYTHONPATH.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>Label</key>
        <string>com.jerry.satimages</string>
        <key>ProgramArguments</key>
        <array>
           <string>python</string>
            <string>/Users/jerrykallam/python_practice/sat_image.py</string>
        </array>
        <!-- ADDED THIS -->
        <key>EnvironmentVariables</key>
        <dict>
            <key>PYTHONPATH</key>
            <string>/your/python/path</string>
        </dict>
        <key>StartInterval</key>
        <integer>360</integer>
        <key>RunAtLoad</key>
        <true/>
    </dict>
</plist>