pyserial: No module named tools

Use pip to install pyserial. First install pip:

sudo apt-get install python-pip

After that install pyserial:

sudo pip install pyserial

You have to uninstall serial and pyserial then reinstall pyserial:

pip uninstall serial
pip uninstall pyserial

pip install pyserial

Because the both libs contain a file named serial.py, you get a name conflict.