why am i encountering the " ModuleNotFoundError: No module named 'yaml' " in ROS?

Question

I have recently begun to learn ROS. whilst running a node file in pycharm, I'm encountering the aforementioned error.

my interpreter is python2.7 and I do have yaml installed for python2.7. I have tried adding a path to the yaml folder but it's still not working. I'm using Ubuntu 18.04.

error message in terminal:

Answer 1

Try:

pip install PyYAML

to install PyYAML