Need to run parameterized python files from Robotframework

I am running python files (as test cases) using the robotframework in my test automation framework. In this python file say I have some parameterized variables (say username). The values for these variables are stored in another python file (say and being passed in the file like:
import data
username =data.val_username

When I am running in my .robot file (say run.robot), how do I mention the reference of the file so that the file can fetch the variable values and run the test. Currently when I execute robot run.robot from the PyCharm’s terminal, it performs no actual action on the UI and exits with a test status as PASS in the console.