Use Python to parse JSON and pythonjson

Use Python to parse JSON and pythonjson

This section describes how to use Python to encode and decode JSON objects.

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

JSON Functions

To use the JSON function, you need to import the json Library:Import json.

Function	Description
Json. dumps	Encodes a Python object into a JSON string.
Json. loads	Decodes the encoded JSON string into a Python object.

Json. dumps

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

Syntax

json.dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, encoding="utf-8", default=None, sort_keys=False, **kw)

Instance

The following example encodes arrays into JSON data:

#!/usr/bin/pythonimport jsondata = [ { 'a' : 1, 'b' : 2, 'c' : 3, 'd' : 4, 'e' : 5 } ]json = json.dumps(data)print json

The code execution result is:

[{"a": 1, "c": 3, "b": 2, "e": 5, "d": 4}]

Use parameters to format the output of JSON data:

>>> import json>>> print json.dumps({'a': 'Runoob', 'b': 7}, sort_keys=True, indent=4, separators=(',', ': ')){    "a": "Runoob",    "b": 7}

Conversion from the original python type to the json type table:

Python	JSON
Dict	Object
List, tuple	Array
Str, unicode	String
Int, long, float	Number
True	True
False	False
None	Null

Json. loads

Json. loads is used to decode JSON data. This function returns the Data Type of the Python field.

Syntax

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 jsonjsonData = '{"a":1,"b":2,"c":3,"d":4,"e":5}';text = json.loads(jsonData)print text

The code execution result is:

{u'a': 1, u'c': 3, u'b': 2, u'e': 5, u'd': 4}

Json type conversion to python type table:

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

 

Use a third-party Library: Demjson

Demjson is a third-party python module library that can be used to encode and decode JSON data. It contains the formatting and validation functions of JSONLint.

Github address: https://github.com/dmeranda/demjson

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

Environment Configuration

Before using Demjson to encode or decode JSON data, we need to install the Demjson module. In this tutorial, We will download Demjson and install:

$ tar -xvzf demjson-2.2.3.tar.gz$ cd demjson-2.2.3$ python setup.py install

More Installation Introduction view: http://deron.meranda.us/python/demjson/install

JSON Functions

Function	Description
Encode	Encodes a Python object into a JSON string.
Decode	Decodes the encoded JSON string into a Python object.

Encode

The Python encode () function is used to encode a Python object into a JSON string.

Syntax

demjson.encode(self, obj, nest_level=0)

Instance

The following example encodes arrays into JSON data:

#!/usr/bin/pythonimport demjsondata = [ { 'a' : 1, 'b' : 2, 'c' : 3, 'd' : 4, 'e' : 5 } ]json = demjson.encode(data)print json

The code execution result is:

[{"a":1,"b":2,"c":3,"d":4,"e":5}]

Decode

Python can use the demjson. decode () function to decode JSON data. This function returns the Data Type of the Python field.

Syntax

demjson.decode(self, txt)

Instance

The following example shows how Python decodes a JSON object:

#!/usr/bin/pythonimport demjsonjson = '{"a":1,"b":2,"c":3,"d":4,"e":5}';text = demjson.decode(json)print  text

The code execution result is:

{u'a': 1, u'c': 3, u'b': 2, u'e': 5, u'd': 4}