Python Set Math Challenge Task 2

COURSES = {
    "Python Basics": {"Python", "functions", "variables",
                      "booleans", "integers", "floats",
                      "arrays", "strings", "exceptions",
                      "conditions", "input", "loops"},
    "Java Basics": {"Java", "strings", "variables",
                    "input", "exceptions", "integers",
                    "booleans", "loops"},
    "PHP Basics": {"PHP", "variables", "conditions",
                   "integers", "floats", "strings",
                   "booleans", "HTML"},
    "Ruby Basics": {"Ruby", "strings", "floats",
                    "integers", "conditions",
                    "functions", "input"}
}

def covers(set_topics):
    course_list = []
    for topic, course in COURSES.items():
        if set_topics.intersection(course):
            course_list.append(topic)
    return course_list

def covers_all(single_set):
        all_courses = []
    for topic, course in COURSES.items():
        if single_set.issubset(course):
            all_courses.append(topic)
    return all_courses