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Python Python Collections (2016, retired 2019) Sets Set Math

Olivia Earenfight
Olivia Earenfight
3,509 Points
Posted by Olivia Earenfight
Olivia Earenfight
3,509 Points

Not sure where to start - Math Set Python

I'm working on the first challenge for the covers challenge and i can't figure out where to start. I understand what the question is asking me to do, but I'm not sure where to even begin writing this code. I know that for every item in the key of these dictionaries I need to look for intersections with the other sets and then return the courses that have those lists, I just can't figure out how to do intersections on lists that aren't defined, but are looped through.

sets.py 
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):
    results = []
    for key in COURSES:
        if topics.intersection(COURSES.[key])
    return results

1 Answer

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

My solution:

  • Go through the COURSES dictionary using a for loop
  • Get the intersection between the current course's topics and the topics parameter
  • If the intersection contains something, and is not an empty list, that means there's a topic covered in the current course that we want. Therefore, we append the course's name to our list of course names
  • Return the course names
def covers(topics):
    result_courses = []
    for course_name, course_topics in COURSES.items():
        if course_topics.intersection(topics):
            result_courses.append(course_name)
    return result_courses

Solving problems like these take practice, so I wouldn't worry too much! Just do a lot of them, and eventually they'll be as easy as cake! :wink: