Gestión de estructuras JSON anidadas

Introducción

Acceso a claves anidadas

import json
data = {'user': {'address': {'city': 'NYC', 'zip': '10001'}}}
print(data['user']['address']['city'])

Acceso seguro a datos anidados

data = {'user': {'name': 'Alice'}}
city = data.get('user', {}).get('address', {}).get('city', 'unknown')
print(city)

Iteración sobre arrays de objetos

import json
data = json.loads('[{"name":"Alice"},{"name":"Bob"}]')
for user in data:
    print(user['name'])

Aplanado de JSON anidado

def flatten(d, prefix=''):
    result = {}
    for k, v in d.items():
        key = f'{prefix}.{k}' if prefix else k
        if isinstance(v, dict):
            result.update(flatten(v, key))
        else:
            result[key] = v
    return result
print(flatten({'a': {'b': {'c': 1}}, 'd': 2}))

Filtrado de arrays

data = [{'name':'A','active':True},{'name':'B','active':False}]
active = [u for u in data if u.get('active')]
print(active)

Transformación de datos anidados

data = [{'id': 1, 'name': 'Alice'}, {'id': 2, 'name': 'Bob'}]
names = [d['name'] for d in data]
print(names)

Validación de esquemas con jsonschema

# from jsonschema import validate
# schema = {'type':'object','required':['name']}
# validate({'name':'Alice'}, schema)  # OK
# validate({}, schema)  # raises ValidationError
print('schema validation demo')

Actualización profunda de diccionarios anidados

def deep_update(base, override):
    for k, v in override.items():
        if isinstance(v, dict) and isinstance(base.get(k), dict):
            deep_update(base[k], v)
        else:
            base[k] = v
    return base
result = deep_update({'a': {'x': 1}}, {'a': {'y': 2}})
print(result)

Consultas al estilo de jq con Python

def find_all(obj, key):
    if isinstance(obj, dict):
        if key in obj: yield obj[key]
        for v in obj.values(): yield from find_all(v, key)
    elif isinstance(obj, list):
        for item in obj: yield from find_all(item, key)
data = {'a': {'name': 'x'}, 'b': [{'name': 'y'}]}
print(list(find_all(data, 'name')))

Serialización a NDJSON

import json
objects = [{'id': 1}, {'id': 2}, {'id': 3}]
ndjson = '\n'.join(json.dumps(o) for o in objects)
print(ndjson)

Comprobación rápida

Resumen

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