如何从这个json对象中获取值

{
  "name": "John",
  "age": 30,
  "address": {
    "street": "123 Main St",
    "city": "New York"
  },
  "hobbies": ["reading", "running", "cooking"]
}

json_obj = {
  "name": "John",
  "age": 30
}

name = json_obj.name
age = json_obj.age

json_obj = {
  "name": "John",
  "age": 30
}

name = json_obj['name']
age = json_obj['age']

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

street = json_obj.address.street
city = json_obj.address.city

json_obj = {
  "name": "John",
  "age": 30,
  "hobbies": ["reading", "running", "cooking"]
}

first_hobby = json_obj.hobbies[0]
second_hobby = json_obj.hobbies[1]