Question

I don’t have much experience in software design yet so I’m not sure how programmers typically solve this type of problem. I basically am creating some values and storing them in a dict, but the names are not unique. I know its not possible to store same key names in dicts but how do software engeeners get around this problem(I’m sure I’m not the first to face this)?

I think some code will make it easier to understand(two lists, one of animals and fruits, and then generating a random value between the two. I’m trying to figure out how to store this data so I can use it later):

lista = ['dog', 'cat', 'elephant', 'pig', 'bear']
listb = ['apple', 'pear']

dict_of_lists_values = {}
for list_a in lista:
    for list_b in listb:
        #print list_a, list_b
        #print lista.index(list_a), listb.index(list_b), lista.index(list_a) *  listb.index(list_b)
        dict_of_lists_values[list_a] = [lista.index(list_a) *  listb.index(list_b), list_b]

for lists_data in dict_of_lists_values:
    print lists_data, ' holds ', dict_of_lists_values[lists_data]

You see the end result is:

elephant  holds  [2, 'pear']
pig  holds  [3, 'pear']
dog  holds  [0, 'pear']
bear  holds  [4, 'pear']
cat  holds  [1, 'pear']

which makes total sense because its overwriting the previous results(which would contain apple in the list of list and not pear). How can I redesign this if I want to store all 10 results and not just the unique 5?

thanks in advance.

Answer 1

You can use a combined key. For example you could use a tuple of a element from each list as key so you’d have:

dict_of_lists_values[(list_a, list_b)] = lista.index(list_a) *  listb.index(list_b)

And then to get the same output:

for lists_data in dict_of_lists_values:
    print lists_data[0], ' holds ', dict_of_lists_values[lists_data], lists_data[1]