CODEWITHSUNDEEP
pythonpython-3.xdictionary
cookie1986
cookie1986

Reputation: 895

Combining nested python dictionarys based on a shared key

I have two nested dictionaries I am looking to combine. The keys on the outermost dictionaries are the same (A,B,C in this instance), but they differ on the inner-dictionaries.

dict1 = {'A': {'red': 4, 'yellow': 2, 'blue': 5}, 'B': {'orange': 1, 'purple': 2, 'green': 2}, 'C': {'black': 1, 'purple': 2, 'red': 2}}
dict2 = {'A': {'white': 1}, 'B': {'white': 2}, 'C': {'white': 3}}

What I want to do is create a new dictionary by adding the 'white' dictionary entry in dict2 to the corresponding entry in dict1 (based on their shared outer-keys). Ultimately, what I want to end up with is this:

finaldict = {'A': {'red': 4, 'yellow': 2, 'blue': 5, "white": 1}, 'B': {'orange': 1, 'purple': 2, 'green': 2, "white": 2}, 'C': {'black': 1, 'purple': 2, 'red': 2, "white": 3}}

Note: The order in which 'white' appears within each dictionary isn't a problem.

I have tried using the defaultdict function from collections but so far have only been able to group the two dictionaries at the outer-level

finaldict = defaultdict(list)
for d in (dict1, dict2):
    for key, value in d.items():
        data[key].append(value)

Upvotes: 0

Views: 35

Answers (2)

Mykola Zotko
Mykola Zotko

Reputation: 17884

You can use the following dictcomp:

{key: {**dict1[key], **dict2[key]} for key in dict1.keys() | dict2.keys()}

Output:

{'A': {'red': 4, 'yellow': 2, 'blue': 5, 'white': 1},
 'B': {'orange': 1, 'purple': 2, 'green': 2, 'white': 2},
 'C': {'black': 1, 'purple': 2, 'red': 2, 'white': 3}}

Upvotes: 0

Rakesh
Rakesh

Reputation: 82785

Use dict.update

Ex:

dict1 = {'A': {'red': 4, 'yellow': 2, 'blue': 5}, 'B': {'orange': 1, 'purple': 2, 'green': 2}, 'C': {'black': 1, 'purple': 2, 'red': 2}}
dict2 = {'A': {'white': 1}, 'B': {'white': 2}, 'C': {'white': 3}}

for k, v in dict1.items():
    key = dict2.get(k)
    if key:
        v.update(key)
print(dict1)

Output:

{'A': {'blue': 5, 'red': 4, 'white': 1, 'yellow': 2},
 'B': {'green': 2, 'orange': 1, 'purple': 2, 'white': 2},
 'C': {'black': 1, 'purple': 2, 'red': 2, 'white': 3}}

OR if you need a separate dict

result = {}
for k, v in dict1.items():
    key = dict2.get(k, {})
    result.setdefault(k, {}).update({**v, **key})

Upvotes: 1

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