DSA snippets

dfs.py

def dfs(obj, key) -> dict | list | None:
    """
    Finds an item and returns values
    Args:
        obj (dict | list): object
        key (str): target key
    Returns:
        dict | list | None
    """
    # Handle dicts
    if isinstance(obj, dict):
        if key in obj:
            return obj[key]

        for v in obj.values():
            r = dfs(v, key)
            if r is not None:
                return r

    # Handle lists and tuples
    elif isinstance(obj, (list, tuple)):
        for v in obj:
            r = dfs(v, key)
            if r is not None:
                return r
    return None

DFS for returning the items of a key if it exists