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

Annika Noren
Annika Noren
26,930 Points
Posted by Annika Noren
Annika Noren
26,930 Points

My code works in workspaces, but not in in the code challenge. It is challenge #4 of 5: def most_courses

Here is my code (it works in workspaces):

def most_courses(my_dict): pairs = {} for teacher in my_dict: counter = 0 for course in my_dict[teacher]: counter += 1 pairs.update({teacher : counter}) max_value = max(pairs.values()) max_key = [k for k, v in pairs.items() if v == max_value] return(max_key)

I realize it is not as clean as other solutions, but I'd still like to figure out why it doesn't pass.

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(my_dict):
    return(len(my_dict))

def num_courses(my_dict):
    return(sum(len(value) for value in my_dict.values()))

def courses(my_dict):
    course_list = list()
    for teacher in my_dict.keys():
        for course in my_dict[teacher]:
            course_list.append(course)
    return(course_list)         

def most_courses(my_dict):
    pairs = {}
    for teacher in my_dict:
        counter = 0
        for course in my_dict[teacher]:
            counter += 1
            pairs.update({teacher : counter})
    max_value = max(pairs.values())
    max_key = [k for k, v in pairs.items() if v == max_value]
    return(max_key)

4 Answers

John Goodwin
John Goodwin
17,921 Points
John Goodwin
John Goodwin
17,921 Points

Hi Annika,

I copied and pasted your code from the code block and it passed the challenge. I'm not sure why it isn't passing for you. This is the part after teachers.py, not the few lines at the top.

Annika Noren
Annika Noren
26,930 Points
Annika Noren
Annika Noren
26,930 Points

Hi John, Thank you for confirming my code (not the stuff at the top, but the code in the black space.) I appreciate your time

Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 28,716 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 28,716 Points

You did a really nice job on the coding this up. But the automated test wants a STR return rather than a LIST type return. One modification should make it work for you, see below comment on last line.

You are well prepared for the last part of the challenge with your "pairs" dictionary concept.

Best of luck on your Python journey, may it bring you great rewards!

def most_courses(my_dict):
    pairs = {}
    for teacher in my_dict:
        counter = 0
        for course in my_dict[teacher]:
            counter += 1
            pairs.update({teacher : counter})
    max_value = max(pairs.values())
    max_key = [k for k, v in pairs.items() if v == max_value]
    return(max_key[0]) # return the first item and it will work
Annika Noren
Annika Noren
26,930 Points
Annika Noren
Annika Noren
26,930 Points

Thank you, Jeff! Much appreciated.