Sunglasses

A brand of sunglasses identifies their models using two codes (strings). The first code, size code, represents the size and consists of two digits, indicating the diameter of the glass, followed by a hyphen and two digits more, indicating the length of the bridge. For example, the code '52-14' represents a model with a diameter of 52 and a bridge length of 14. The second code, identification code, indicates the model name, for example, 'RB2014'.

The brand stores the information of the different models available in a dictionary, where the key is a size code and the value is a list of identification codes that are available for that size. For example, the pair '52 -14': ['RB2014', 'RB2514', 'RJ2014'] indicates that for the size code '52-14' there are the following models 'RB2014', 'RB2514' and 'RJ2014'.

In the module sunglasses (file sunglasses.py), write the function diameters() that given a dictionary as described, return a new dictionary where each key is a diameter and each value is the list of models with this diameter, sorted alphabetically. Both the diameter and the models in the resulting dictionary are strings. In this new dictionary there must be as many keys as there are different diameters in the given dictionary and the list associated with each key cannot contain repeated models.

For example:

>>> du = {
... '52-14':['RB2014','RB2213','RJ2014'],
... '54-14':['RJ2014','RB2514'],
... '52-16':['RJ2514','RB2014'],
... '55-14':['RB2014']
... }
>>> dr = diameters(du)
>>> if dr != {
... '52':['RB2014','RB2213','RJ2014','RJ2514'],
... '54':['RB2514','RJ2014'],
... '55':['RB2014']
... }:
...    print(dr)

More tests are provided in file test-diameters.txt.

Solution:

A solution is provided in file sunglasses.py.