Python find value in nested dictionary

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In Python3 we can build a simple generator to get all values from a nested dictionary. See below simple example code for it:-

def get_values(d):
    for v in d.values():
        if isinstance(v, dict):
            yield from get_values(v)
        else:
            yield v


a = {4: 1, 6: 2, 7: {8: 3, 9: 4, 5: {10: 5}, 2: 6, 6: {2: 7, 1: 8}}}

print(list(get_values(a)))

Output:

Get all keys of a nested dictionary

Here is code that would print all team members:

Liverpool = {
    'Keepers': {'Loris Karius': 1, 'Simon Mignolet': 2, 'Alex Manninger': 3},
    'Defenders': {'Nathaniel Clyne': 3, 'Dejan Lovren': 4, 'Joel Matip': 5, 'Alberto Moreno': 6, 'Ragnar Klavan': 7,
                  'Joe Gomez': 8, 'Mamadou Sakho': 9}
}


for k, v in Liverpool.items():
    for k1, v1 in v.items():
        print(k1)

Output:

Retrieve list of values from nested dictionaries

Iterates through the elements of the list and checks the type of each element based on the ‘id‘ and ‘children‘ naming convention.

mylist = [
    {u'id': 5650,
     u'children': [
         {u'id': 4635},
         {u'id': 5648}
     ]},
    {u'id': 67,
     u'children': [
         {u'id': 77}
     ]}
]


def extract_id_values(mylist):
    ids_to_return_list = []

    for element in mylist:
        for key, value in element.items():
            if 'id' == key:
                ids_to_return_list.append(value)
            if 'children' == key:
                for children_elem in value:
                    if 'id' in children_elem:
                        ids_to_return_list.append(children_elem['id'])
    return ids_to_return_list


print(extract_id_values(mylist))

Output: [5650, 4635, 5648, 67, 77]

Using list comprehension + values() + keys()

test_dict = {'Gfg': {"a": 7, "b": 9, "c": 12},
             'is': {"a": 15, "b": 19, "c": 20},
             'best': {"a": 5, "b": 10, "c": 2}}

# initializing key
key = "c"

# using keys() and values() to extract values
res = [sub[key] for sub in test_dict.values() if key in sub.keys()]

print(res)

Output: [12, 20, 2]

Using list comprehension + items()

test_dict = {'Gfg': {"a": 7, "b": 9, "c": 12},
             'is': {"a": 15, "b": 19, "c": 20},
             'best': {"a": 5, "b": 10, "c": 2}}

# initializing key
key = "a"

# using item() to extract key value pair as whole
res = [val[key] for keys, val in test_dict.items() if key in val]

print(res)

Output: [7, 15, 5]

Source: stackoverflow.com

Do comment if you have any doubts and suggestions on this Python dictionary list topic.

Note: IDE: PyCharm 2021.3.3 (Community Edition)

Windows 10

Python 3.10.1

All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.

Degree in Computer Science and Engineer: App Developer and has multiple Programming languages experience. Enthusiasm for technology & like learning technical.

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