Merge Multiple Dictionaries When Their Keys Have A List Of Values Python

I came across a post that had a complete and correct way of merging two dictionaries, when each dictionary has for each key a list of values. The input of the program is something

Solution 1:

There is no need to iterate over pairs of dictionaries, as set().union() operation can take multiple arguments:

defmerge_dictionaries(*args):
    result = {}
    for key inset().union(*args):
        # let's convert the value union to set before sorting to get rid of the duplicates
        result[key] = sorted(set.union(*[set(d.get(key, [])) for d in args]), key=int)
    return result

Solution 2:

You have a typo: you used dict where you meant dicts.