python set playground

pg.py

# Let's write some functions to explore set math a bit more.
# We're going to be using this COURSES dict in all of the examples. Don't change it, though!
# So, first, write a function named covers that accepts a single parameter, a set of topics.
# Have the function return a list of courses from COURSES where the supplied set and the course's value (also a set) overlap.
# For example, covers({"Python"}) would return ["Python Basics"].

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(topics):
    res = set()
    for (key, val) in COURSES.items():
        if topics & val:
            res.update(topics & val)
    return list(res)

def covers_refactor(topics):
    return [key for (key, val) in COURSES.items() if topics & val]

covers({'Python'}) # ['Python Basics']