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

Jamaru Rodgers
Jamaru Rodgers
3,046 Points
Posted by Jamaru Rodgers
Jamaru Rodgers
3,046 Points

Finding teacher w/ max num of course

Maximum headache achieved! lol Please help! I've been doing this code for about 2 hours by myself because I wanted to figure this out, but I've tried everything I know to do..

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(arg):
    count = len(arg)
    return count
def num_courses(arg):
    total = 0
    for teacher in arg.values():
        for course in teacher:
            total += 1
    return total    
def courses(arg):
    course_list = []
    for teacher in arg.values():
        for course in teacher:
            course_list.append(course)
    return course_list
def most_courses(arg):
    max_count = 0
    correct_list = []
    for teacher in arg.keys():
        if len(teacher) > max_count:
            max_count = len(teacher)
    for teacher in arg.keys():
        if len(teacher) == max_count: 
            correct_list.append(teacher)
    return correct_list
Jamaru Rodgers
Jamaru Rodgers
3,046 Points
Jamaru Rodgers
Jamaru Rodgers
3,046 Points

The only error it's throwing is that I'm not getting all the teacher names. And yes, I know I used arg.keys() instead of .values(), but it was saying that same error before when I was.

1 Answer

Pete P
Pete P
7,613 Points
Pete P
Pete P
7,613 Points 
if len(teacher) > max_count:

This piece of code above is checking the length of the key, rather than the length of the list that the key corresponds to. To check the length of the list of courses it should look like this:

if len(arg[teacher]) > max_count:

Also, make sure you are returning just the name of the teacher with the most courses, not a list with name(s).

Your code could be changed to look something like:

def most_courses(arg):
    max_count = 0
    correct_teacher = ''  #  Note: this is not a list
    for teacher in arg.keys():
        if len(arg[teacher]) > max_count:
            #  update max_count
            #  update correct_teacher

    return correct_teacher

Hopefully these hints help. If not, write back and let me know where you're getting stuck.