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

Posted by Maxmillan Muchena
Maxmillan Muchena
2,478 Points

stuck on set math part 2

how can i get my code to work properly

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):
    course_list=[]
    for course,sets in COURSES.items():
        if topics.intersection(sets):
            course_list.append(course)
    return course_list

def covers_all(topics,*args):
    course_list=[]
    for course,sets in COURSES.items():
        for topic in topics:
            if topics.intersection(sets):
                course_list.append(course)
    return course_list

2 Answers

Maxmillan Muchena
Maxmillan Muchena
2,478 Points
Maxmillan Muchena
Maxmillan Muchena
2,478 Points

Finally cracked it .

def covers_all(topics):
    course_list =[]
    topics=set(topics)
    for course, sets in COURSES.items():
        if (topics-sets)==set() :
            course_list.append(course)
    return course_list
Mathew Yangang
Mathew Yangang
4,433 Points

Hi Maxmillan, can you please explain how you came up with lines 3,4, and 5, beginning from where you set topics = set(topics). I'm also stuck on the same problem

Maxmillan Muchena
Maxmillan Muchena
2,478 Points
Maxmillan Muchena
Maxmillan Muchena
2,478 Points

line 3 - I changed the topics argument into a set so that I could use the set methods. line 4 - The for statement will loop through all items in the dictionary COURSES line 5 - Here the if statement checks if there is a difference between the topics from input and the topics in COURSES. If there is a difference it will mean that the course(in COURSES) doesn't have all the items from the topics we input. line 6 - if there was no difference then that course will be added to the course_list which is then returned

I hope that made a bit of sense.

Mathew Yangang
Mathew Yangang
4,433 Points

Okay i see. Thanks Maxmillan