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

Posted by Austin Liu
Austin Liu
3,326 Points

Code works as expected in my terminal, but challenge says I don't have the right output

Tried covers({"strings"}) and got ['Python Basics', 'Java Basics', 'PHP Basics', 'Ruby Basics'], as expected. Also tried covers({"loops"}) and covers({"Python"}) and got expected outputs.

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):
    li = []
    for x in COURSES:
        if topics & COURSES[x] == topics:
            li.append(x)
    return li

1 Answer

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

You are very close. The if condition is overly specific.

# This says "if the *all* the supplied topics are covered in the course *x*"
        if topics & COURSES[x] == topics:

# The challenge is only looking if *any* of the supplied topics are in each course *x*

I'll leave the change needed for you to figure out. Hint: it's a simpler condition than above!

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