Import Error: paho.mqtt.client not found

I think I have found the problem,

You have installed Python3 but for some reason the interpreter defaults to version 2.7 in Linux.

Try using pip3 install paho-mqtt python-etcd instead.

Or if it does not work, you can literally copy and paste the paho folder from your Python2.7 site-packages folder to your Python3 site-packages folder. I have just verified paho-mqtt 1.2 for Python2 is exactly the same as paho-mqtt 1.2 for Python3 using a Meld diff tool. Please note, when you directly copy and paste pip list will not display the package you copied.

site-packages are usually inside your system lib folder. It depends upon how Python is installed. In my case everything is inside $HOME/.pyenv folder.

Remember Python2 has it's own site-packages folder and Python3 has it's own site-packages folder where Python searches for the packages. Sometimes if you are using a Debian based Linux distro please make sure to check inside the dist-packages folder as well to see if you can find the package you are looking for.

You can try install Paho lib:

git clone https://github.com/eclipse/paho.mqtt.python

Once you have the code, it can be installed from your repository as well:

cd paho.mqtt.python
python setup.py install