Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

victor E
victor E
19,146 Points
Posted by victor E
victor E
19,146 Points

i am having a hard time converting this into a list of courses. list() and return do not give correct output

i am having a hard time converting this into a list of courses. list() and return do not give correct output

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):
    for key, value in COURSES.items():
        if topics in COURSES[key]:
            print (key)

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

Remember that "topics" is a set, so it's not likely to be found (in it's entirety) as a member of the set of topics associated with one of the courses.

What you're looking for is any overlap (any items in common) between the set passed in as the argument and one associated with a course. One of the "set math" operators could be handy here.

victor E
victor E
19,146 Points
victor E
victor E
19,146 Points

thanks for the tip, this is how i got the right answer! def covers(topics): lst = [] for key, value in COURSES.items(): if topics & COURSES[key]: lst.append(key) return lst