如何通过python在json中选择对象的特定key/value

import json

json_data = '{"name": "John", "age": 30, "city": "New York"}'
data = json.loads(json_data)

value = data["key"]

import json

json_data = '{"name": "John", "age": 30, "city": "New York"}'
data = json.loads(json_data)

value = data["key"]
print(value)

json_data = '{"person": {"name": "John", "age": 30, "city": "New York"}}'

value = data["person"]["key"]