You’re misunderstanding :) You’re trying to find correlation between two variables x and y. For example, x may be the day of the week and y may be the color of shirt you’re wearing. So you’ll pass the function these two lists: x = [‘Sunday’, ‘Sunday’, ’Monday’, ’Tuesday’], y = [‘yellow’, ’green’, ‘green’, ‘blue’]. These correspond to the fact that you wore a yellow shirt on some Sunday and a green shirt on another Sunday, a green shirt on a Monday a blue shirt on a Tuesday.