title: Python3- fail to find `paho` module
body: <p>I have a python code to operate using <code>paho-mqtt</code>, which run OK from command line, but when I try to run it as service during boot process, it fails.</p>
  
  <p>looking in <code>/var/log/daemon.log</code> shows that it fails since it does not find module.</p>
  
  <pre><code>Jul 20 09:13:34 HomePi_Win1 python3[208]:   File "/home/guy/github/RemoteSwitch/mqtt_switch.py", line 3, in &lt;module&gt;
  Jul 20 09:13:34 HomePi_Win1 python3[208]:     import paho.mqtt.client as mqtt
  Jul 20 09:13:34 HomePi_Win1 python3[208]: ImportError: No module named 'paho'
  </code></pre>
  
  <p>not liking solutions as adding path in code:</p>
  
  <pre><code>from sys import path
  path.append('/home/guy/.local/lib/python3.5/site-packages/paho')
  import paho.mqtt.client as mqtt
  from threading import Thread
  import time
  </code></pre>
  
  <p>BUT - still got the same message.</p>
  
  <p>What else can be done ?</p>