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

Prasanna kadel
PLUS
Prasanna kadel
Courses Plus Student 1,057 Points
Posted by Prasanna kadel
Prasanna kadel
Courses Plus Student 1,057 Points

please help

Great work! OK, let's create something a bit more refined. Create a new function named covers_all that takes a single set as an argument. Return the names of all of the courses, in a list, where all of the topics in the supplied set are covered. For example, covers_all({"conditions", "input"}) would return ["Python Basics", "Ruby Basics"]. Java Basics and PHP Basics would be exclude because they don't include both of those topics.

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):
    l=[]
    for keys,value in COURSES.items():
        if value&a:
            l.append(keys)
    return l

1 Answer

Jason Freitas
Jason Freitas
6,716 Points
Jason Freitas
Jason Freitas
6,716 Points

The key here is to use sets for the comparison, which I think is where you are heading with the "&" or intersection operator in your "if" statement. As you probably know the function argument "a" may include a collection of topics.

In the loop, you will need to convert the list of topics for each "key" into a set, set(COURSES[keys]). How about a statement to check that the length of the output of the intersection is greater than zero?

If the comparison is true, that means there are some common elements.

if len(set(a) & set(COURSES[keys])) > 0: l.append(keys)

Something like that should work...