Python :访问JSON元素

import json

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

name = data["name"]
age = data["age"]
city = data["city"]

print(name, age, city)

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

name = data.get("name")
age = data.get("age")
city = data.get("city")

print(name, age, city)

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

class Person:
    def __init__(self, name, age, city):
        self.name = name
        self.age = age
        self.city = city

person = Person(**data)

name = person.name
age = person.age
city = person.city

print(name, age, city)