[Tutor] Nested dictionary with defaultdict

[John Fouhy]

On 16/04/2008, GTXY20 <gtxy20 at gmail.com> wrote:
> I currently have a dictionary like the following:
>
> {'1': ['220', '220', '220''], '2': ['220', '238', '238', '238', '238'], '3':
> ['220', '238'], '4': ['220', '220'], '5': ['220', '220', '238'], '6':
> ['238', '238'], '7': ['220']}
>
> I am trying to create a dictionary that would list the current key and a
> count of the iterations of values within the value list like so:
>
> {'1': {'220' : 3}, '2': {'220' : 1}, 2: {238 : 4}, '3': {'220' : 1}, 3: {
> '238' : 1}, '4': {220 : 2}, '5': {'220: 2}, '5': {238 : 1}, '6': {'238' :
> 2}, '7': {'220' : 1}}
[...]
> I am looking for a satrting point or any suggestions.

Can you write a function that will take a list and return a dictionary
with the counts of elements in the list?

i.e. something like:

>>> def countValues(valueList):
...  # your code goes here
...
>>> countValues(['220', '238', '238', '238', '238'])
{'238': 4, '220': 1}

P.S.  Your sample output is not a valid dictionary...

-- 
John.