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

Michael Carlson
Michael Carlson
5,934 Points
Posted by Michael Carlson
Michael Carlson
5,934 Points

I have a solution that works within the workspace environment, but i'm told it's not giving the right input...

I've put together a solution to this problem that, best I can tell, works in the workspaces environment. The error message on the code challenge isn't specific enough to be helpful in identifying why my code isn't considered a proper solution.

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):
    classes=[]
    for course_title in COURSES.keys():
        if topics.intersection(COURSES[course_title]) == topics:
            classes.append(course_title)
    return classes

1 Answer

Jerson Otzoy
Jerson Otzoy
1,532 Points
Jerson Otzoy
Jerson Otzoy
1,532 Points

Hello,

Just remove the comparison in the if statement

if topics.intersection(COURSES[course_title]):
            classes.append(course_title)

In your case you are expecting the intersection to be the same as the topics, but what happens when for example we call the function as this:

covers({"Python", "Java"})

This should return Python basics and Java basics, as you can see removing the comparison with topics will check if there is an intersection, at least one item from topics is contained in a course.