如何将JSON值转换为键值对pir

import json

def json_to_dict(json_str):
    json_dict = json.loads(json_str)
    return json_dict

def flatten_dict(json_dict, parent_key='', sep='.'):
    items = []
    for key, value in json_dict.items():
        new_key = f"{parent_key}{sep}{key}" if parent_key else key
        if isinstance(value, dict):
            items.extend(flatten_dict(value, new_key, sep=sep).items())
        else:
            items.append((new_key, value))
    return dict(items)

def json_to_key_value_pairs(json_str):
    json_dict = json_to_dict(json_str)
    key_value_pairs = flatten_dict(json_dict)
    return key_value_pairs

{
  "name": "John",
  "age": 30,
  "address": {
    "street": "123 Main St",
    "city": "New York"
  }
}

[
  ("name", "John"),
  ("age", 30),
  ("address.street", "123 Main St"),
  ("address.city", "New York")
]