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

Idan shami
Idan shami
13,251 Points
Posted by Idan shami
Idan shami
13,251 Points

help me understand something... task 3 teacher stats

hi (: I am having some problems with this task.... when I am trying the code in work spaces it gives me 5 lists and not all of the values in 1 list, so I tried looking at others answer and I found this one

def courses(a_dict):
    course_list = []
    for teachers in a_dict:
        for courses in a_dict[teachers]:
            course_list.append(courses)
    return course_list

why is he using 2 loops? and what a_dict[teacher] does that affect the list to be 1...? can I do it with the .value() statement?

I really appreciate your help! thanks!

Idan.

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.
teachers_course = {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],'KennethLove': ['Python Basics', 'Python Collections']}
def num_teachers(teachers_course):
    count = 0
    for teacher in teachers_course:
        if teacher in teachers_course:
            count += 1
        else:
            count = 0
    return count

def num_courses(teachers_course):
    count_course = 0
    for course in teachers_course.values():
        if course in teachers_course.values():
            count_course += len(course)
        else:
            count_course = 0
    return count_course

def courses(teachers_course):
    values_list = []
    for value in teachers_course.values():
        values_list.append(value)
        return values_list
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.

# 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.
teachers_course = {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],'KennethLove': ['Python Basics', 'Python Collections']}
def num_teachers(teachers_course):
    count = 0
    for teacher in teachers_course:
        if teacher in teachers_course:
            count += 1
        else:
            count = 0
    return count

def num_courses(teachers_course):
    count_course = 0
    for course in teachers_course.values():
        if course in teachers_course.values():
            count_course += len(course)
        else:
            count_course = 0
    return count_course

def courses(teachers_course):
    values_list = []
    for value in teachers_course.values():
        values_list.append(value)
        return values_list

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,453 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,453 Points

In your attached code snippet:

def courses(a_dict):
    course_list = []
    for teachers in a_dict:  # <-- teacher is each key in a_dict
        for courses in a_dict[teachers]:  # <-- a_dict[teachers] will be the list of courses
                                          # courses will be each course in the list of courses
            course_list.append(courses)  # <-- append course to course_list
    return course_list

But, since a_dict[teachers] is a list already, it can be added to the courses_list directly and skip the inner for loop with

    course_list.extend(a_dict[teachers])

Your posted code, is very close to the solution!

def courses(teachers_course):
    values_list = []
    for value in teachers_course.values():
        values_list.append(value) # <-- use extend instead of append otherwise you'll get a list of list
        return values_list  # <-- return value indented too far

Post back if you need more help. Good luck!!