This is what worked for me. Oddly I felt like i had entered this several times, and kept getting the error, does your code accept anything other than n or y ? Now it seems to be working. I tired adding a break inside the while loop at the end, but it did not allow for a user to enter in answers other than n and y repeatedly. This code allows for the user to repeatedly enter other responses until they choose y or n.
choice = raw_input('Enjoying the course? (y/n)')
while choice != "y" and choice != "n":
choice = raw_input("Sorry, I didn't catch that. Enter again: ")