Walk a collection, like a JSON object, using a callback.

walkcollection.py

import logging
from collections.abc import Iterable 

def is_container(obj):
    return isinstance(obj, Iterable) and not isinstance(obj, (str, bytes, bytearray))

# https://stackoverflow.com/a/54000999/394430
def walk_collection(obj, callback=None, _path: list=[], **kwargs):
    """Walk an arbitrarily nested structure of lists and/or dicts such as would be made when
    reading JSON as an object. Walking is performed in a depth-first search manner.

    Args:
        obj (dict, list, set, tuple): Container object, possibly nested.
        callback (function, optional): If specified, this function gets called on each node
            when the algorithm has arrived at it. It must accept at least two first arguments: 
            the current node, and the path to that node. Defaults to None.
        kwargs (dict, optional): If `callback` is used, this permits kwargs to be passed to 
            that function. Defaults to None.
    """
    if isinstance(obj, dict):
        if callback:
            callback(obj, _path, **kwargs)
        for k,v in obj.items():
            if is_container(v) is False:
                if callback:
                    _path.append(k)
                    callback(v, _path, **kwargs)
                    _path.pop()
            elif isinstance(v, list) or isinstance(v, set):
                _path.append(k)
                if callback:
                    callback(v, _path, **kwargs)
                for elem in v:
                    walk_collection(elem, callback, _path, **kwargs)
                _path.pop()
            elif isinstance(v, dict):
                _path.append(k)
                walk_collection(v, callback, _path, **kwargs)
                _path.pop()
            else:
                logging.warning(f'Type "{type(v).__name__}" not recognized: {".".join(_path)}. key={k}, val={v}')
    elif isinstance(obj, list):
        if callback:
            callback(obj, _path, **kwargs)
        for elem in obj:
            walk_collection(elem, callback, _path, **kwargs)
    elif callback and is_container(obj) is False:
        callback(obj, _path, **kwargs)