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

Thomas McDonnell
Thomas McDonnell
8,212 Points
Posted by Thomas McDonnell
Thomas McDonnell
8,212 Points

Any help with this one

I feel think I am greatly over thing this here. The below passes in my ipyhton in terminal but fails here in the challenge workspace. I know it looks terribly un pythonic but I continued down the line solving the issues as I went and just ended up with this. Returning intersections alone gave an un-concatenated list so I concatenated it, which gave a string and than converted it back to a list :)

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(a):
    intersections = []
    for course in COURSES:
        if COURSES[course] & a == a:
            intersections += course
    courses_covered = "".join(intersections)
    cover = [courses_covered]
    return cover

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

You are being more restrictive than necessary. By using

        if COURSES[course] & a == a:

you are testing that a is a proper subset of course (this is what task 2 will look for in covers_all). For Task 1, a simple overlap is sufficient:

        if COURSES[course] & a:

Additionally, Task 1 is looking for a list to be returned. You already have this in intersections. Return interactions

Post back if you need more help. Good luck!!