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Python Python Collections (Retired) Dictionaries Teacher Stats

Mar Bocatcat
Mar Bocatcat
7,405 Points
Posted by Mar Bocatcat
Mar Bocatcat
7,405 Points

Stuck on 'Stats Challenge' task 3 of 4

I cant seem to figure this one out. I am new to thinking like a programmer so any type of help is appreciated!

Output: Bummer! Didn't get the expected output. Got ['Andrew Chalkley',4].

teachers.py 
# The dictionary will be something like:
# {'Jason Seifer': ['Ruby Foundations', 'Ruby on Rails Forms', 'Technology Foundations'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Often, it's a good idea to hold onto a max_count variable.
# Update it when you find a teacher with more classes than
# the current count. Better hold onto the teacher name somewhere
# too!
#
# Your code goes below here.
def most_classes(dictionary):
  max_count = 0
  teacher_name = ''
  for teacher in dictionary:
    len_class = len(dictionary[teacher])
    if (len_class) > (max_count):
      max_count = len_class
      teacher_name = teacher
  return teacher_name

def num_teachers(dictionary):
  for teachers in dictionary:
    num_teachers = len(dictionary)
  return num_teachers

def stats(dictionary):

  new_list = []
  for teachers in dictionary:
    list_teachers = teachers
  for classes in dictionary:
    list_class = len(dictionary[classes])
  new_list = [list_teachers, list_class]
  return new_list
Mar Bocatcat
Mar Bocatcat
7,405 Points
Mar Bocatcat
Mar Bocatcat
7,405 Points

The one i am having trouble with is the last function 'def stats(dictionary'. Please let me know if i missed any details. Thanks!

1 Answer

Tatiana Jamison
Tatiana Jamison
6,188 Points

What is your intent with list_teachers and list_class? It seems like you want to append values, but right now, you're just assigning the most recent value (so that list_teachers gets overwritten X times, rather than having X items in an array).

Mar Bocatcat
Mar Bocatcat
7,405 Points
Mar Bocatcat
Mar Bocatcat
7,405 Points

Thanks for the reply! Sorry i am really new to this kind of thinking, I intended to put the key and the value to their list and then combine them in a (name, classes ) kind of way. Since the objective is to list them that way

Tatiana Jamison
Tatiana Jamison
6,188 Points

Sure! In that case, try the .append() method for list items -- so list_teachers.append(teachers). If you get stuck on a challenge, it's often useful to open up a Workspace to try to accomplish a similar task - it might not be exactly the same as the challenge, but it could give you some useful information!

I looked over the challenge as it's been a while, and I think you'll want to review the "dictionary iteration video." When you call the key for the dictionary, you have access to all the information you need - so you can do a single for loop inside the stats() function.... Remember to initialize new_list, as you've done, then for each key in the dictionary, append a list (remember, using the square brackets []) of the teacher name and number of classes. (You calculated those before for the most_classes() function.)

And there's definitely no need to apologize for being new -- we all start out as beginners!

Mar Bocatcat
Mar Bocatcat
7,405 Points
Mar Bocatcat
Mar Bocatcat
7,405 Points

Thank you so much for your help! Okay i took your advice and I thought i figured it out but still unable to get the output that they want.

def stats(listNames): teachers = []

for teach in listNames:
    teachers.append(teach)
    classes = len(listNames[teach])
    teachers.append(classes)

print teachers

The output is [Name, Number of classes , Name, Number of classes ] but its still wrong. Im not sure what im doing wrong.

Tatiana Jamison
Tatiana Jamison
6,188 Points

Rad! You're really, really close! Look back at the original question: the challenge is asking for a list of lists. Can you make the item you're appending in each iteration (currently, the teacher's name and # of classes) into a list that has that teacher's name and # of classes?

Mar Bocatcat
Mar Bocatcat
7,405 Points
Mar Bocatcat
Mar Bocatcat
7,405 Points

I did this: ef courses(listNames): courses = [] for teacher in listNames: courses.append(teacher) classes = listNames[teacher] courses.append(classes)

print courses

and it worked! Thank you so much for your help! Im glad you didnt give me the answer and just gave me hints. You really helped me a lot! Thanks again!

Tatiana Jamison
Tatiana Jamison
6,188 Points

Great job! One of the things that I find really exciting about programming is that different people can solve the same problem in different ways. Mine looked more like this:

def stats(dictionary):
    list = []
    for teacher in dictionary:
        list.append([teacher, len(dictionary[teacher]))
    return list

I'm glad that you kept working at it until you found a solution!

Mar Bocatcat
Mar Bocatcat
7,405 Points
Mar Bocatcat
Mar Bocatcat
7,405 Points

Yours look a lot cleaner than mine was! Thank you again for the help , i might need your help again if i get stuck again -_-

Thanks!