Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

Why this code is producing error ?

Where i am wrong with my approach ?

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(values):
    teachers_list=[]
    for key in values.keys():
        if key not in teachers_list:
            teachers_list.append(key)
        return len(teachers_list)

1 Answer

William Li
PLUS
William Li
Courses Plus Student 26,868 Points

indentation problem.

You put this line return len(teachers_list) inside the for loop, that's a mistake, you should only return the length of teachers_list list after the for loop is done.