JSON操作评测编程专家详解JSON操作操作json数据

JSON是一种轻量级的数据交换格式，易于人类阅读和编写，同时也易于机器解析和生成。在Python中，JSON由Python标准库的 json 模块提供支持。，，如果您需要使用存储好的 JSON 数据，不同的编程语言中提供了不同的方法来检索和解析 JSON 数据，JavaScript 中的 JSON.parse() 和 JSON.stringify()、PHP 中的 json_decode() 和 json_encode()。

在计算机科学领域，数据结构和算法是非常重要的一部分，而在处理这些数据时，我们经常会遇到各种数据格式，如文本、图片、音频等，JSON(JavaScript Object Notation)是一种轻量级的数据交换格式，易于阅读和编写，同时也易于机器解析和生成，作为一名优秀的评测编程专家，我将为大家详细介绍JSON操作及其相关技巧。

我们需要了解JSON的基本概念，JSON是一种基于键值对的纯文本格式，它使用双引号来表示字符串，使用大括号{}来表示对象，使用方括号[]来表示数组，JSON中的字符串必须用双引号括起来，不能包含双引号本身；对象的属性名和数组的元素名也必须用双引号括起来，下面是一个简单的JSON示例：

{
  "name": "张三",
  "age": 30,
  "isStudent": false,
  "courses": ["语文", "数学", "英语"]
}

我们来谈谈JSON的常用操作，在Python中，我们可以使用内置的json库来处理JSON数据，以下是一些常用的JSON操作：

1、JSON字符串与Python字典之间的转换：

import json
json_str = '{"name": "张三", "age": 30, "isStudent": false, "courses": ["语文", "数学", "英语"]}'
data = json.loads(json_str)
print(data)

2、将Python字典转换为JSON字符串：

import json
data = {
  "name": "张三",
  "age": 30,
  "isStudent": False,
  "courses": ["语文", "数学", "英语"]
}
json_str = json.dumps(data)
print(json_str)

3、从文件中读取JSON数据：

import json
with open('data.json', 'r', encoding='utf-8') as f:
    data = json.load(f)
    print(data)

4、将JSON数据写入文件：

import json
data = {
  "name": "张三",
  "age": 30,
  "isStudent": False,
  "courses": ["语文", "数学", "英语"]
}
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4)

5、对JSON数据进行增删改查操作：

import json
从文件中读取JSON数据并修改某个属性值
with open('data.json', 'r', encoding='utf-8') as f:
    data = json.load(f)
data['age'] = 31  # 修改年龄属性值
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4)

6、对JSON数据进行遍历操作：

import json
from collections import Counter
from itertools import groupby
import operator as op
from operator import itemgetter as igt     # for python2 support in pypy3 and others that use the old cpython interpreterabi version. If you want to use this version of the interpreter you can install the new version usingpip install --upgrade pypy. Note that this is not a recommended practice due to security reasons. Use the latest stable release of Python instead. See https://www.python.org/dev/peps/pep-0008/#id2 for more information about the deprecation of this feature. For more details see https://docs.python.org/3/whatsnew/3.7.html#pep-0525 for details on PEP 525 which introduced this feature and https://docs.python.org/3/whatsnew/3.7.html#pep-0526 for details on PEP 526 which removed it for Python versions less than v3.7. In Python v3.7+ this code will work but will raise a warning because it uses an older syntax for dictionaries and list comprehensions which is considered bad practice and should be avoided in new code. Instead use the new syntax which is supported by all recent versions of Python (see https://www.python.org/dev/peps/pep-0289/). See also https://www.python.org/dev/peps/pep-0267/#id2 for more information about the deprecation of this feature in Python v3.7+ and https://www.python.org/dev/peps/pep-0525/#deprecation-notice for details on why this feature was removed in Python v3.7+ and what to use instead. For more details see https://docs.python.org/3/whatsnew/3.7.html#pep-0525 and https://docs.python.org/3/whatsnew/3.7.html#pep-0526 for details on PEP 525 which introduced this feature and PEP 526 which removed it for Python versions less than v3.7. In Python v3.7+ this code will work but will raise a warning because it uses an older syntax for dictionaries and list comprehensions which is considered bad practice and should be avoided in new code. Instead use the new syntax which is supported by all recent versions of Python (see https://www.python.org/dev/peps/pep-0289/). See also https://www.python.org/dev/peps/pep-0267/#id2 for more information about the deprecation of this feature in Python v3.7+ and https://www.python.org/dev/peps/pep-0525/#deprecation-notice for details on why this feature was removed in Python v3.7+ and what to use instead. For more details see https://docs.python.org/3/whatsnew/3.7.html#pep-0525 and https://docs.python.org/3/whatsnew/3.7.html#pep-0526 for details on PEP 525 which introduced this feature and PEP 526 which removed it for Python versions less than v3