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Parsing Nested JSON in Python
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Parsing Nested JSON in Python

MediumPython

Problem

Perficient data pipelines often receive nested JSON payloads from Adobe Experience Manager and other content systems. Write a function that flattens a JSON object into a dictionary whose keys identify each leaf value by its path.

Formal Specification

Implement flatten_json(data), where data is a JSON-compatible object represented by a Python dictionary. Traverse nested dictionaries and lists:

  1. Join dictionary keys with ..
  2. Represent list positions with bracket notation, such as items[0].
  3. Store primitive values and None at their complete paths.
  4. Treat an empty dictionary or list as a leaf and store it unchanged.
  5. The root object itself is not assigned a path. An empty root object returns {}.

Dictionary keys contain only letters, digits, and underscores, so path escaping is not required. Return a new dictionary. Output key order is not significant.

Constraints

  • The root value is a dictionary.
  • 1 <= number of JSON values <= 10^4.
  • Nesting depth is at most 100.
  • Values are valid JSON types: dictionaries, lists, strings, numbers, booleans, and None.
  • Dictionary keys contain only letters, digits, and underscores.

Function Signature

def flatten_json(data):
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