https://hackersandslackers.com/extract-data-from-complex-json-python/

json_extract.py

"""Extract nested values from a JSON tree."""


def json_extract(obj, key):
    """Recursively fetch values from nested JSON."""
    arr = []

    def extract(obj, arr, key):
        """Recursively search for values of key in JSON tree."""
        if isinstance(obj, dict):
            for k, v in obj.items():
                if isinstance(v, (dict, list)):
                    extract(v, arr, key)
                elif k == key:
                    arr.append(v)
        elif isinstance(obj, list):
            for item in obj:
                extract(item, arr, key)
        return arr

    values = extract(obj, arr, key)
    return values

Super useful function, thanks all. Here's @Fjurg 's code with added type hinting and more explicit parameter names

 from typing import Dict, List, Union, Any


def extract_values(object_to_search: Union[Dict[Any, Any], List[Any]], search_key: str) -> List:
    """Recursively pull values of specified key from nested JSON."""
    results_array: List = []

    def extract(object_to_search: Union[Dict[Any, Any], List[Any]], results_array: List[Any], search_key: str) -> List:
        """Return all matching values in an object."""
        if isinstance(object_to_search, dict):
            for key, val in object_to_search.items():
                if isinstance(val, (dict, list)):
                    if key == search_key:
                        results_array.append(val)
                    extract(val, results_array, search_key)
                elif key == search_key:
                    results_array.append(val)
        elif isinstance(object_to_search, list):
            for item in object_to_search:
                extract(item, results_array, search_key)
        return results_array

    results = extract(object_to_search, results_array, search_key)
    to_return = []
    for result in results:
        if type(result) == list:
            for item in result:
                to_return.append(item)
        else:
            to_return.append(result)
    return to_return