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

Sandra Gury
Sandra Gury
6,911 Points
Posted by Sandra Gury
Sandra Gury
6,911 Points

Set Math challenge task 1 of 2

My code returns me this: treehouse:~/workspace$ python test.py
['P', 'y', 't', 'h', 'o', 'n', ' ', 'B', 'a', 's', 'i', 'c', 's'] I don't get why... Can anybody help me with that?

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 (topic):
    list_of_courses =[]

    for key in COURSES:
        if topic & COURSES[key]:
            list_of_courses.extend(key)
        else:
            continue
    return(list_of_courses)

1 Answer

ursaminor
ursaminor
11,271 Points
ursaminor
ursaminor
11,271 Points

You need to use append() instead of extend(). extend() is adding each item (ie, character) from the course name to list_of_courses. Take a look here: https://stackoverflow.com/questions/252703/difference-between-append-vs-extend-list-methods-in-python

Also, there is no need for else: continue. The loop will not do anything to the item if it doesn't fit the condition.