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

Fernando Santos
Fernando Santos
11,267 Points
Posted by Fernando Santos
Fernando Santos
11,267 Points

I can't realize what is wrong

The code is running as required on my workspace, but they don't accept it in the code challenge. I can't realize what's wrong.

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):
    answer = []
    for course in COURSES.keys():
        if COURSES[course]&topics == topics:
            answer.append(course)
    return answer

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,457 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,457 Points

You are very close. You currently are logically anding whether a course is in Courses (always True) and whether topics is equivalent to itself (also, always True).

Perhaps you meant to and two sets which returns a "truthy" value if there exists common elements:

        COURSES[course] & topics:

Also, the default condition when looping over a dict is to use the dict keys. So the following two are equivalent:

    for course in COURSES.keys():

    for course in COURSES

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