Trying to do check every combination of classes for a schedule

[Anonymous No.7560989]

I'm writing a schedule optimizer in python. I have a list of courses (let's say 5 for example) and each course is an object with 3 attributes, each of which corresponding to a list of the lectures, tutorials, and labs, respectively. I need to check every lecture/tutorial/lab combination for each course with every lecture/tutorial/lab combination for each of the other courses.

The problem I'm running into is structuring a bunch of nested for loops to take care of this. If a course has no tutorials or no labs for example, the nested for loops would need to double in size. That is, I would need an if statement which checks for any tutorials/labs for each of those and nests for loops accordingly. I have no idea how to organize this search for all the combinations. Any help would be great.