Best way to merge elements of a dictionary python

Question

I am facing a problem where I have to merger different elements of a dictionary based on some condition. What is the most pythonic way to achieve that?

For example , I have the below dictionary

dict = {
    'a': [element1 , element2]
    'b': [element2, element3]
    'c': [element4, element5, element1]
    'd': []
}

My resulting dictionary should be

dict = {
 'a': [element1, element2, element3, element4, element5]
}

What would be the best way to achieve that?

I want to merge them based upon condition which is evaluated by is_compatible method. So lets' say I will merge two elements if this function returns true Is there a way I can do this?

Looks like its a connected component problem https://stackoverflow.com/questions/53886120/combine-lists-with-common-elements/53886179#53886179 — yatu, May 06 '20 at 14:50
@DavidS You can consider the quality of elements as a condition and key does n't matter here — Deepanshu Arora, May 06 '20 at 14:52
Does this have to extend to multiple "connected lists"? Or just one? — yatu, May 06 '20 at 15:02
So what would the output be with an additional entry: `'d': ['element9']` — yatu, May 06 '20 at 15:03
see python dictionary : dict = {'a': [ep1 , ep2],'b': [ep2, ep3],'c': [ep4, ep5, ep1],'d': []} — Cătălin George Feștilă, May 06 '20 at 15:16

score 4 · Answer 1 · answered May 06 '20 at 14:54

4

result = {
    'a': list(set().union(*input_dict.values()))
}

answered May 06 '20 at 14:54

Marat

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score 0 · Answer 2 · answered May 06 '20 at 14:58

I don't clearly get what you want to do, but it seems like you want to combine all lists as a set. You can do something like this:

new_list = []
for element in dict.values():
    for value in element:
        new_list.append(element)
new_list = list(set(new_list))
new_dict = {
    dict.keys[0]: new_list
}

Hope this helps!

Best way to merge elements of a dictionary python

2 Answers2