ImportError: No module named _imagingtk

You need to install ImageTk module.

In debian, ubuntu, you can use following command to install it:

sudo apt-get install python-imaging-tk

UPDATE

If you're using recent version of ubuntu (16.04+), the package name changed.

• python-pil.imagetk (Python 2.x)
• python3-pil.imagetk (Python 3.x)

As noted by falsetru, you need to install the ImageTk module first: it doesn't automatically come with Python. To do this, run one of the commands below:

If you're using Python 2.x, use this command:

sudo apt-get install python-imaging-tk

If you're using Python 3.x, use this command:

sudo apt-get install python3-pil.imagetk