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Python Python Collections (Retired) Dictionaries Teacher Stats

Yosef Fastow
Yosef Fastow
18,526 Points

Problem with the first part of teacher progect

If one has the value of a dictionary saved in a variable how could you get the key of that value? In Teacher Stats my program is returning the value and I can't get the key.

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(teachers):
    best = 0
    bestest = []
    for teacher in teachers.values():
        classes = teachers
        if len(teacher) > best:
            best = len(teacher)
            bestest = teacher
    return bestest
Afrid Mondal
Afrid Mondal
6,255 Points

Instead of iterate of its value (teachers.values()) only iterate over teacher. You will get your key.

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,426 Points

When iterating over a dictionary, the default behavior is iterating over the keys.

for teacher in teachers:

# is equivalent to 

for teacher in teachers.keys():

If you want to work with both keys and values use items

for teacher, courses in teachers.items():
Yosef Fastow
Yosef Fastow
18,526 Points

Thanks. It worked perfectly! I used items to loop through the keys and value.