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

Posted by jackyj
jackyj
9,969 Points

teachers.py Challenge Task 5

According to Python Shell, the code is working. However, when I tried to check my work in the challenge, it says "It looks like Task 4 is no longer valid.". I am not sure what I did wrong. I need an extra eye to look at my code. Thanks.

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.

dic = {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'], 'Kenneth Love': ['Python Basics', 'Python Collections']}

def num_teachers(dic):
    return len(dic)

def num_courses(dic):
    sum = 0
    for value in dic.values():
        sum += len(value)
    return sum

def courses(dic):
    liso = []
    for value in dic.values():
        liso += value
    return liso

def most_courses(dic):
    max_count = 0
    teacher_most_classes = " "
    for key in dic:
        if len(dic[key]) > max_count:
            max_count = len(dic[key])
            teacher_most_classes = key
    return key

def stats(dic):
    list_name = []
    list_numcours = []
    for key in dic:
        list_name.append(key)
        list_name.append(len(dic[key]))
        list_numcours.append(list_name)
        list_name = []
    return list_name

6 Answers

Stuart Wright
Stuart Wright
41,119 Points
Stuart Wright
Stuart Wright
41,119 Points

I think you've just made the same mistake as you made in task 4, in that you're simply returning the wrong variable. Try returning list_numcours instead.

Here's my solution which follows the same logic as yours but uses different names for lists which perhaps makes it a little easier to visualize:

def stats(dic):
    outer_list = []
    for key in dic:
        inner_list = []
        inner_list.append(key)
        inner_list.append(len(dic[key]))
        outer_list.append(inner_list)
    return outer_list
Sakari Huuskola
Sakari Huuskola
1,139 Points
Sakari Huuskola
Sakari Huuskola
1,139 Points

This is how I made the last challenge, in my opinion this is nicer to look at

def stats(teachers):
    namelist = [] #empty list
    for teacher, courses in teachers.items(): #for loop to go through the dictionary
        namelist.append([teacher, len(courses)]) #adding stats to the empty list
    return namelist
Stuart Wright
Stuart Wright
41,119 Points
Stuart Wright
Stuart Wright
41,119 Points

The error message is correct - task 4 doesn't pass because it is wrong. You need to return 'teacher_most_classes', not 'key'.

As for task 5 itself, I can tell from just the last two lines that it will return an empty list every time.

jackyj
jackyj
9,969 Points

What would I need to change for task 5? I have tried several approaches, but none of them seem to work.

Opanin Akuffo
Opanin Akuffo
4,713 Points
Opanin Akuffo
Opanin Akuffo
4,713 Points

Try this, worked for me and its shorter.

def stats(dic):
    table = []
    for key in dic:
        count = len(dic[key])
        table += [[key, count]]
    return table
Michael Moore
Michael Moore
7,121 Points
Michael Moore
Michael Moore
7,121 Points

Mine isn't accepted in Treehouse submission to pass the challenge, but it results in the correct outcome when running the code in workshops.

def stats(dictionary):
    teachers_class_list = list()
    i = 0
    for key, value in dictionary.items():
        teachers_class_list.insert(i, [key])
        if isinstance(value, list):
            teachers_class_list[i].append(len(value))
        else:
            teachers_class_list[i].append(1)
        i+=1

  return(teachers_class_list)

when passing in

dictionary = {"John Love": ["python", "cyclops"], "Emmett Vernon":"c++", "Jacob Carroll":["fixing", "sinks", "handyman"], "Michael Moore":["ruby", "calculus", "physics", "meaning of life"], "Maxx Maxx":"css"}
stats(dictionary)

it results in:

[['John Love', 2], ['Emmett Vernon', 1], ['Michael Moore', 4], ['Jacob Carroll', 3], ['Maxx Maxx',             
 1]]

Can anyone tell me why it wasn't accepted?

f4u57
f4u57
6,743 Points
f4u57
f4u57
6,743 Points

It wasn't easy but I did it!

def stats(my_dict):
    list = []
    for teacher, course_list in my_dict.items():
        num_course = len(course_list)
        list.append([(teacher), num_course])
    print(list)