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

Posted by Annie Livingstone
Annie Livingstone
1,844 Points

Could someone tell me why my code isn't returning the right output?

I've checked out other answers and seen an answer that works:

def covers(set_of_topics): output = [] for course, value in COURSES.items(): if set_of_topics & value: output.append(course) return output

But I'm still not seeing why mine doesn't work! Anyone have an answer? Thanks!

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(set_of_topics):
    output = []
    for course in COURSES:
        if set_of_topics & COURSE[course]:
            output += course
    return output

1 Answer

Dave StSomeWhere
Dave StSomeWhere
19,870 Points
Dave StSomeWhere
Dave StSomeWhere
19,870 Points

Two issues pop out to me (try executing your code and these should be easy to see), Glad to see you are using intersection here - the main focus of the challenge.

  1. You reference COURSE[course] - shouldn't that be COURSES[course]
  2. Your assignment will be like extend() and add each letter of your string literal as an entry in your output variable. Try using append() and you should pass. (would be worthwhile to test and see the difference between the two).

:palm_tree: :tropical_drink:

Annie Livingstone
Annie Livingstone
1,844 Points

Thanks Dave! Super helpful!