Python - json.load() 和 json.loads() 的区别

JSON（JavaScript Object Notation）是一种由编程语言中的文本组成的脚本（可执行）文件，用于存储和传输数据。它是一种独立于语言的格式，非常容易理解，因为它本质上是自我描述的。 Python有一个名为 json 的内置包。在本文中，我们将看到 Json.load 和 json.loads() 方法。这两种方法都用于从带有文件的 Unicode字符串中读取和写入。

json.load()

json.load()接受一个文件对象并返回 json 对象。它用于从文件中读取 JSON 编码的数据并将其转换为Python字典并反序列化文件本身，即它接受文件对象。

Syntax: json.load(fp, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)

Parameters:

fp: File pointer to read text.

object_hook: It is an optional parameter that will be called with the result of any object literal decoded.

parse_float: It is an optional parameter that will be called with the string of every JSON float to be decoded. 

parse_int: It is an optional parameter that will be called with the string of every JSON int to be decoded.

object_pairs_hook: It is an optional parameter that will be called with the result of any object literal decoded with an ordered list of pairs.

例子：

首先创建json文件：

Python3

import json
  
data = {
    "name": "Satyam kumar",
    "place": "patna",
    "skills": [
        "Raspberry pi",
        "Machine Learning",
        "Web Development"
    ],
    "email": "[e-mail]",
    "projects": [
        "Python Data Mining",
        "Python Data Science"
    ]
}
with open( "data_file.json" , "w" ) as write:
    json.dump( data , write )

输出：

数据文件.json

之后，创建 json 文件，让我们使用 json.load()：

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with open("data_file.json", "r") as read_content:
    print(json.load(read_content))

输出：

{‘name’: ‘Satyam kumar’, ‘place’: ‘patna’, ‘skills’: [‘Raspberry pi’, ‘Machine Learning’, ‘Web Development’],
’email’: ‘[e-mail]’, ‘projects’: [‘Python Data Mining’, ‘Python Data Science’]}

json.loads()

json.loads()方法可用于解析有效的 JSON字符串并将其转换为Python字典。它主要用于将 JSON 数据组成的原生字符串、字节或字节数组反序列化为Python字典。

Syntax: json.loads(s, encoding=None, cls=None, object_hook=None, parse_float=None, parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)

Parameters:

s: Deserialize str (s) instance containing a JSON document to a Python object using this conversion table.

object_hook: It is an optional parameter that will be called with the result of any object literal decoded.

parse_float: It is an optional parameter that will be called with the string of every JSON float to be decoded. 

parse_int: It is an optional parameter that will be called with the string of every JSON int to be decoded.

object_pairs_hook: It is an optional parameter that will be called with the result of any object literal decoded with an ordered list of pairs.

例子：

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import json 
    
# JSON string: 
# Multi-line string 
data = """{ 
    "Name": "Jennifer Smith", 
    "Contact Number": 7867567898, 
    "Email": "[e-mail]", 
    "Hobbies":["Reading", "Sketching", "Horse Riding"] 
    }"""
    
# parse data: 
res = json.loads( data ) 
    
# the result is a Python dictionary: 
print( res )

输出：

{‘Name’: ‘Jennifer Smith’, ‘Contact Number’: 7867567898, ‘Email’: ‘[e-mail]’,
‘Hobbies’: [‘Reading’, ‘Sketching’, ‘Horse Riding’]}