How to assign an input to an existing list in python 3 : I'm struggling to figure this one out... I have lists of subjects (english, math and so on) with the names of students in each one, and my objective is to give the program the names of two subjects, and then receive two new lists with the names that only appear in the one subject, and names that only appear in the other subject. Some students are in several classes, you see. My problem is that python treats my input variable class1 and class2 as strings, and doesn't assign them to the existing list in the program, even though I'm assigning them to the names of the lists. I hope someone can help and I apologize for the total shit explanation of my problem - first time posting in here ;)

    english=['eve','beatrice','tim','tom']
    math=['tim','tom','mary','fiona']
    spanish = ['tim','mary','jürgen','mike']
    geography = ['farquard','fiona','shrek','donkey']

    class1,class2 = input('what classes do you want to work with? ').split(',')
    
    class1_clean = []
    for name in class1:
        if name in class2:
            continue
        class1_clean.append(name)
    print(class1_clean)
    
    class2_clean = []
    for name in class2:
        if name in class1:
            continue
        class2_clean.append(name)
    print(class2_clean)