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Rodrigue Loredon
1,338 PointsI can't figure out how to write the nested for loops to get a count of the teachers's courses in the teachers.py script
Hi, I've been on this for 24 hours and still can't figure it out.
# The dictionary will be something like:
# 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.
teachers = {'Jason Seifer': ['Ruby Foundations', 'Ruby on Rails Forms', 'Technology Foundations'],
'Kenneth Love': ['Python Basics', 'Python Collections']}
def most_classes(teachers):
max_count = 0
course_number = 0
teacher_with_most_classes =''
3 Answers
Chris Freeman
Treehouse Moderator 68,441 PointsHi Rodrigue, You don't necessarily need nested loops (a loop within a loop) for this task.
A bit of background: A dictionary can be iterated over in several ways using a for loop as shown in the ipython session below.
# define a dictionary
In [24]: d1 = {'a': 1, 'b': 2}
# list keys of dictionary
In [25]: d1.keys()
Out[25]: dict_keys(['a', 'b'])
# use keys() to create iterable list of keys
In [26]: for key in d1.keys():
print(key)
....:
a
b
# list values of dictionary
In [29]: d1.values()
Out[29]: dict_values([1, 2])
# use values() to create iterable list of values
In [30]: for value in d1.values():
print(value)
....:
1
2
# list key value pairs of dictionary as Tuples
In [27]: d1.items()
Out[27]: dict_items([('a', 1), ('b', 2)])
# use items() to create iterable list of key value tuples
In [28]: for item in d1.items():
print(item)
....:
('a', 1)
('b', 2)
# list key value pairs of dictionary as Individual items
In [31]: d1.items()
Out[31]: dict_items([('a', 1), ('b', 2)])
# use items() to create iterable list of key value individually
In [32]: for key, value in d1.items():
....: print(key, value)
....:
a 1
b 2
# The default assumption is to iterate over the keys:
In [33]: for key in d1:
....: print(key)
....:
a
b
Using the default method, you can iterate over the dictionary keys like this:
def most_classes(teachers):
max_count = 0
course_number = 0
teacher_with_most_classes =''
# loop over each key in teachers dictionary
for teacher in teachers:
# check if the length of this teacher's class list is a new max
if len(teachers[teacher]) > max_count:
# save this teacher as new max
max_count = len(teachers[teacher])
teacher_with_most_classes = teacher
# return max teacher name
return teacher_with_most_classes
[**Edit**: added missing max_count assignment --cf]
Rodrigue Loredon
1,338 PointsHello Chris, I appreciate your help thank you but I wasn't able to pass that challenge. I even tried copy pasting your code but the script still doesn't return the right teacher. Take care
Chris Freeman
Treehouse Moderator 68,441 PointsOops! I forgot to update max_count. See corrected answer above.
Rodrigue Loredon
1,338 PointsAwsome! It works and helped my understanding a lot. Thank you VERY VERY MUCH :)