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Python Python Collections (Retired) Dictionaries Teacher Stats

Posted by Kevin Li
Kevin Li
2,634 Points

I don't get how I'm wrong (Code Challenge)

I'm on part 3 of the Code Challenge. When I enter my code as it is below, it says that "'str' object has no attribute 'append'".

I'm pretty sure it's pointing to the third to last line. However, I don't think item is a string, because I made sure that it was a list, as you can see in the last function, stats. How can I get the correct answer?

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(dict):
    max_count = 0
    max_teacher = None
    for key in dict:
        count = 0
        value = dict[key]
        for item in value:
            count += 1
            if count > max_count:
                max_count = count
                max_teacher = key
    return max_teacher
def num_teachers(dict):
    teacher_count = 0
    for key in dict:
        teacher_count += 1
    return teacher_count
def stats(dict):
    dict_list = []
    for key in dict:
        count = 0
        item = []
        item.append(key)
        for item in dict[key]:
            count += 1
        item.append(count)
        dict_list.append(item)
    return dict_list
Tonye Jack
.a{fill-rule:evenodd;}techdegree
Tonye Jack
Full Stack JavaScript Techdegree Student 12,469 Points

you cant append count because its not an iterable your just increasing the value of count and still storing it in the count variable name.

def stats(teacher_dict):
    teachers  = []
    total = []
    result = []
    for k,v in teacher_dict.items():
        teachers.append(k)
        total.append(len(v))
    for t in teachers:
        result.append([t,total[teachers.index(t)]])
    return result
Kevin Li
Kevin Li
2,634 Points

Oh okay. Thanks!

1 Answer

Steven Parker
Steven Parker
229,644 Points
Steven Parker
Steven Parker
229,644 Points

You've already declared and assigned item when you get to this line:

        for item in dict[key]:

At that point it gets re-used to iterate through the strings of class names, ending up as one of the strings. But then you do this:

        item.append(count)

And that causes the error.

:point_right: You might want to pick a different variable name to iterate through the list of classes.

Kevin Li
Kevin Li
2,634 Points

Thank you so much! I didn't realize that.