如何迭代嵌套的字典(计数器)和递归更新键

def update_nested_dict(dictionary, key_value):
    key, value = key_value
    if key in dictionary:
        if isinstance(dictionary[key], dict) and isinstance(value, dict):
            dictionary[key] = update_nested_dict(dictionary[key], value)
        else:
            dictionary[key] += value
    else:
        dictionary[key] = value
    return dictionary

# 示例用法
counter = {'a': {'b': {'c': 1}}}
key_value = ('c', 2)
updated_counter = update_nested_dict(counter, key_value)
print(updated_counter)

{'a': {'b': {'c': 3}}}