Python JSON uses

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Shows you how to encode and decode JSON objects using the Python language.

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for people to read and write.

JSON functions

Use JSON functions to import the JSON library: importJSON.

function	Description
Json.dumps	Encode a Python object as a JSON string
Json.loads	Decodes an encoded JSON string into a Python object

Json.dumps

The json.dumps is used to encode a Python object into a JSON string.

Grammar

Json.Dumps(Obj,Skipkeys=False,Ensure_ascii=True,Check_circular=true, Allow_nan=true< Span class= "pun" >, Cls=none Indent=none, Separators=none, encoding = "utf-8" , default< Span class= "pun" >=none, Sort_keys=false, **kw               /span>                

Instance

The following example encodes an array into JSON-formatted data:

#!/usr/bin/pythonImportJsondata= [ { A : 1, ' B ' : 2,  ' C ' : 3,  : 4  ' E '  :  5 } ]json = Json. (data) print< Span class= "PLN" > json              

The result of the above code execution is:

[{"a":1,"C":3,"B":2,"E":5,"D" :4}]                 

Use parameters to format the output of JSON data:

>>> ImportJson>>> PrintJson.Dumps({A: ' Runoob ',  ' B ' : 7 }, Sort_keys=true,< Span class= "PLN" > Indent=4, separators< Span class= "pun" >= ( ', ' ,  ': ' {  "a" : "Runoob" ,  "B" : 7}        

Python primitive type conversion table to JSON type:

Python	JSON
Dict	Object
List, tuple	Array
STR, Unicode	String
int, long, float	Number
True	True
False	False
None	Null

Json.loads

The json.loads is used to decode JSON data. The function returns the data type of the Python field.

Grammar

JSON.  Loads(s[, encoding[, cls[, object_hook[, parse_float[, Parse_ int[, parse_constant[, object_pairs_hook[,* *kw]  ]] []] 

Instance

The following example shows how Python decodes a JSON object:

#!/usr/bin/pythonImport=' {' A ': 1, ' B ': 2, ' C ': 3, ' d ': 4, ' E ': 5} ';  = json.  Loads(jsondata)print text          

The result of the above code execution is:

{u' A ':1, u 'C ':3, u 'B ':2, u' E ': 5, u' d ':4}            

JSON type conversion to Python type comparison table:

JSON	Python
Object	Dict
Array	List
String	Unicode
Number (int)	int, long
Number (real)	Float
True	True
False	False
Null	None

Using third-party libraries: Demjson

Demjson is a third-party module library of Python that can be used to encode and decode JSON data, including the Jsonlint formatting and validation functions.

Github Address: Https://github.com/dmeranda/demjson

Official address: http://deron.meranda.us/python/demjson/

Environment configuration

Before using Demjson encoding or decoding JSON data, we need to install the Demjson module first. In this tutorial we will download Demjson and install:

-xvzf Demjson-2.2.  3.tar.  gz$ CD Demjson-2.2.  3$ python setup.  PY Install             

More installation Information view: Http://deron.meranda.us/python/demjson/install

JSON functions

function	Description
Encode	Encode a Python object as a JSON string
Decode	Decodes an encoded JSON string into a Python object

Encode

The Python encode () function encodes a Python object into a JSON string.

Grammar

Demjson.  Encode(self, obj, nest_level=0)       

Instance

The following example encodes an array into JSON-formatted data:

#!/usr/bin/pythonImportDemjsondata= [ { A : 1, ' B ' : 2,  ' C ' : 3,  : 4  ' E '  :  5 } ]json = Demjson. (data) print< Span class= "PLN" > json              

The result of the above code execution is:

[{"a":1,"B":2,"C":3,"D":4,"E"  :5}]                  

Decode

Python can use the Demjson.decode () function to decode JSON data. The function returns the data type of the Python field.

Grammar

Demjson.  Decode(self, txt)      

Instance

The following example shows how Python decodes a JSON object:

#!/usr/bin/pythonImport=' {' A ': 1, ' B ': 2, ' C ': 3, ' d ': 4, ' E ': 5} ';  = Demjson.  Decode(json)print text          

The result of the above code execution is:

{u' A ':1, u 'C ':3, u 'B ':2, u' E ': 5, u' d ':4}            

Python JSON uses