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Python

Posted by Jacques Plomion
Jacques Plomion
2,446 Points

Difference between set.intersection(otherset) and set.issubset(otherset)

Hi all,

I have this script for the question on sets:

def covers(topics):
    result_list = []
    for course, course_topics in COURSES.items():
        #if topics.issubset(course_topics):
        if topics.intersection(course_topics):            
            result_list.append(course)
    return result_list

when I use issubset, I get an error when I submit my response, but when I use intersection, it works fine. Yet, the ouput is the same in both cases.

Any insights for me?

Thanks

Jack

1 Answer

Dave StSomeWhere
Dave StSomeWhere
19,870 Points

Your results are the same because you didn't try enough test cases. The challenge is looking for "Overlap" which is intersection - and will return all courses that contain any of the passed values. Subset returns the courses that contain all the values.

If you test with:

print(covers({"Python", "functions"}))

# intersection returns - both have functions
['Python Basics', 'Ruby Basics']

# issubset returns - only Python Basics has Python and functions
['Python Basics']

:tropical_drink: :palm_tree:

Jacques Plomion
Jacques Plomion
2,446 Points

That makes sense. Thanks Dave!