Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Python Collections (2016, retired 2019) Dictionaries Teacher Stats

num_courses and dictionaries

I don't understand why this code doesn't work. I tried going simpler and it worked in Visual Studio Code but it doesn't work here.

teachers.py
# The dictionary will look something like:
# {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Each key will be a Teacher and the value will be a list of courses.
#
# Your code goes below here.
def num_teachers(dic):

    teachers = len(dic.keys())

    return teachers
def num_courses(dic):
    zero = 0
    for nums in dic.values():
        jnums = ' '.join(nums)
        courses = zero += int(jnums)
    return(courses)

1 Answer

Brendan Whiting
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Brendan Whiting
Front End Web Development Techdegree Graduate 84,735 Points

dic.values() is going to be a list of lists. I printed out dic.values() of the example dictionary and it sent me this:

dict_values([['jQuery Basics', 'Node.js Basics'], ['Python Basics', 'Python Collections']])

So you need some kind of loop inside a loop. I'm also not sure where you're going with joining the items. My strategy was just to flatten out the list of lists into one list, and then return the length of that list.