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Python Python Collections (Retired) Dictionaries Teacher Stats

kirkbyo
kirkbyo
15,791 Points
Posted by kirkbyo
kirkbyo
15,791 Points

Dictionaries [4/4] Error, Although Code works in workspaces

I keep running into an error on the 4th task of this challenge. The question

Write a function named courses that takes the dictionary of teachers. It should return a list of all of the courses offered by all of the teachers.

My Code

teachers = {
  'Jason Seifer': ['Ruby Foundations', 'Ruby on Rails Forms', 'Technology Foundations'],
  'Kenneth Love': ['Python Basics', 'Python Collections'],
}

def courses(teacher_dict):
  allCourses = []
  for courses in teacher_dict:
    tempCourse = []
    tempCourse.append(teacher_dict[courses])
    allCourses.append(tempCourse)
  return allCourses

courses(teachers)

After I run this code in the challenge, I get an error saying that I returned 5 values instead of 18. Although when I run the same code in workspaces, everything runs fine and all the objects from the 'teacher' dictionary gets returned.

Why is this happening?

Ozzie

1 Answer

Santos Solorzano
Santos Solorzano
3,125 Points
Santos Solorzano
Santos Solorzano
3,125 Points

Hmm, I can't quite help you out with your error, BUT I ran your code on my Mac and got this:

[[['Python Basics', 'Python Collections']], [['Ruby Foundations', 'Ruby on Rails Forms', 'Technology Foundations']]]

Try using extend() instead of append() !!!

append adds an element to a list, extend concatenates the first list with another list!

kirkbyo
kirkbyo
15,791 Points
kirkbyo
kirkbyo
15,791 Points

Thank you! I ended using a different method to originally pass the challenge, but changing it from append to extend did end up working. 

def courses(teacher_dict):
  allCourses = []
  for courses in teacher_dict:
    tempCourse = []
    tempCourse.extend(teacher_dict[courses])
    allCourses.extend(tempCourse)
  return allCourses

Thanks a ton,

Ozzie

Dean McKenzie
Dean McKenzie
11,149 Points
Dean McKenzie
Dean McKenzie
11,149 Points

Thanks Santos, the extend() worked out great!