将嵌套字典中的所有键从camelCase转换为snake_case

我有一本类似这样的字典：

{
     'firstName': 'abc',
     'lastName': 'xyz',
     'favoriteMovies': ['Star Wars', 'The lone ranger'],
     'favoriteCountries': [
          {'country': 'China', 'capitalCity': 'Beiging'},
          {'country': 'India', 'capitalCity': 'New Delhi'}
     ]
}

我想将其转换为snake_case，如下所示

{
    'first_name': 'abc',
    'last_name': 'xyz',
    'favorite_movies': ['Star Wars', 'The lone ranger'],
    'favorite_countries': [
        {'country': 'China', 'capital_city': 'Beiging'},
        {'country': 'India', 'capital_city': 'New Delhi'}
     ]
}  

字典可以是任何长度深度。

我目前的解决方案是

import re

def convert_snake_case_to_camel_case(data):
    required_dict = {}

    for key, value in data.items():
        if type(value) == str:
            new_key = re.sub("([a-z0-9])([A-Z])", r"\1_\2", key).lower()
            required_dict[new_key] = value
        elif type(value) == list and all(list(map(lambda _: isinstance(_, str), value))):
            new_key = re.sub("([a-z0-9])([A-Z])", r"\1_\2", key).lower()
            required_dict[new_key] = value
        elif type(value) == list and all(list(map(lambda _: isinstance(_, dict), value))):
            new_key = re.sub("([a-z0-9])([A-Z])", r"\1_\2", key).lower()
            required_dict[new_key] = list(filter(convert_snake_case_to_camel_case, value))
    return required_dict

但我没有得到嵌套数据的预期结果。

短递归版本：

import re
def to_snake(s):
  return re.sub('([A-Z]\w+$)', '_\\1', s).lower()

def t_dict(d):
   if isinstance(d, list):
      return [t_dict(i) if isinstance(i, (dict, list)) else i for i in d]
   return {to_snake(a):t_dict(b) if isinstance(b, (dict, list)) else b for a, b in d.items()}

data = {'firstName': 'abc', 'lastName': 'xyz', 'favoriteMovies': ['Star Wars', 'The lone ranger'], 'favoriteCountries': [{'country': 'China', 'capitalCity': 'Beiging'}, {'country': 'India', 'capitalCity': 'New Delhi'}]} 
print(t_dict(data))

Output:

{'first_name': 'abc', 'last_name': 'xyz', 
 'favorite_movies': ['Star Wars', 'The lone ranger'], 
 'favorite_countries': [
    {'country': 'China', 'capital_city': 'Beiging'}, 
    {'country': 'India', 'capital_city': 'New Delhi'}
  ]
}