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Python Python Collections (Retired) Dictionaries Teacher Stats

Mit Sengupta
Mit Sengupta
13,823 Points
Posted by Mit Sengupta
Mit Sengupta
13,823 Points

I keep wondering why am I getting 4.

I think I have got it all right but I do not know why I'm failing to return all the dictionaries. Please help me someone. Thanks.

Here's the code:

def courses(teachers):
    output = []
    for courses in teachers.values():
        output = courses
    return output

[MOD: added ```python formatting -cf]

3 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

It looks like you're combining solutions for task 3 and task 4. Your original posted code was very close to the solution. Change the output assignment to use .extend():

# Task 4 of 4
# Great work! Finally, write a function named 'courses' that takes the
# teachers dictionary. It should return a single list of all of the
# courses offered by all of the teachers.
def courses(teachers):
    output = []
    for courses in teachers.values():
        output.extend(courses)  # <-- changed output from assignment to 'extend'
    return output
Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

In many cases, the issue is using .append() to create the list of all courses. The solution usually involves using .extend() so you end up with one list of items instead of a "list of lists" result.

Mit Sengupta
Mit Sengupta
13,823 Points
Mit Sengupta
Mit Sengupta
13,823 Points

This is my current modified code : 

def stats(dicts):
  course = []
  for courses in dicts:
    course.extend(courses)
    return course

and now am getting this error: Bummer! Didn't get the expected output. Got ['Andrew Chalkley']

[MOD: added ```python formatting -cf]

Jason Whitaker
Jason Whitaker
12,252 Points

in your for loop you are just getting the key. it needs to be the key and a count of the values in the list. 

for key in dicts:
    add_to_course_list = [key, len(dicts[key])
    course.extend(add_to_course_list)
return course
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,441 Points

To access the courses, you can use the .items() method

for courses in dicts.items():