如何将json数据转换为python对象，并将键中的无效字符(如空格)替换为点符号访问的有效字符。

import json

def replace_invalid_chars(data):
    if isinstance(data, dict):
        new_data = {}
        for key, value in data.items():
            new_key = key.replace(" ", ".")  # 将空格替换为点符号
            new_data[new_key] = replace_invalid_chars(value)
        return new_data
    elif isinstance(data, list):
        new_data = []
        for item in data:
            new_data.append(replace_invalid_chars(item))
        return new_data
    else:
        return data

json_data = '{"name": "John Doe", "age": 30, "address": {"street": "123 Main St", "city": "New York"}}'
python_obj = json.loads(json_data)

python_obj = replace_invalid_chars(python_obj)

print(python_obj)