Python JSON
In this tutorial you‘ll learn how to read and write JSON-encoded data using Python.
You‘ll see hands-on examples of working with Python‘s built-in “json“ module all the way up
to encoding and decoding custom objects.
Working With JSON Data in Python
The full-form of JSON is JavaScript Object Notation. It means that a script (executable) file which is made of text in a programming language, is used to store and transfer the data. Python supports JSON through a built-in package called json
.
Introduction of JSON in Python :
JSON is a syntax for storing and exchanging data.
JSON is text, written with JavaScript object notation.
Python has a built-in package called json
, which can be used to work with JSON data.
Example
Import the json module:
import json
Parse JSON – Convert from JSON to Python
If you have a JSON string, you can parse it by using the json.loads()
method.
Example
Convert from JSON to Python:
import json # some JSON: x = '{ "name":"John", "age":32, "salary":60000}' # parse x: y = json.loads(x) # the result is a Python dictionary: print(y["age"]) #OUTPUT 32
Convert from Python to JSON
If you have a Python object, you can convert it into a JSON string by using the json.dumps()
method.
Example
Convert from Python to JSON:
import json # a Python object (dict): x = { "name": "John", "age": 32, "salary": 60000 } # convert into JSON: y = json.dumps(x) # the result is a JSON string: print(y) //OUTPUT {"name": "John", "age": 32, "salary": 60000}
You can convert Python objects of the following types, into JSON strings:
- dict
- list
- tuple
- string
- int
- float
- True
- False
- None
Example
Convert Python objects into JSON strings, and print the values:
import json print(json.dumps({"name": "John", "age": 32})) print(json.dumps(["apple", "bananas"])) print(json.dumps(("apple", "bananas"))) print(json.dumps("welcome")) print(json.dumps(52)) print(json.dumps(32.76)) print(json.dumps(True)) print(json.dumps(False)) print(json.dumps(None)) #OUTPUT {"name": "John", "age": 32} ["apple", "bananas"] ["apple", "bananas"] "welcome" 22 32.76 true false null
When you convert from Python to JSON, Python objects are converted into the JSON (JavaScript) equivalent:
Python | JSON |
---|---|
dict | Object |
list | Array |
tuple | Array |
str | String |
int | Number |
float | Number |
True | true |
False | false |
None | null |
Example
Convert a Python object containing all the legal data types:
import json x = { "name": "John", "age": 32, "married": True, "divorced": False, "children": ("Ann","Billy"), "pets": None, "cars": [ {"model": "BMW 230", "mpg": 27.5}, {"model": "Ford Edge", "mpg": 24.1} ] } print(json.dumps(x)) #OUTPUT {"name": "John", "age": 32, "married": true, "divorced": false, "children": ["Ann","Billy"], "pets": null, "cars": [{"model": "BMW 230", "mpg": 27.5}, {"model": "Ford Edge", "mpg": 24.1}]}
Format the Result
The example above prints a JSON string, but it is not very easy to read, with no indentations and line breaks.
The json.dumps()
method has parameters to make it easier to read the result:
Example
Use the indent
parameter to define the numbers of indents:
import json x = { "name": "John", "age": 32, "married": True, "divorced": False, "children": ("Ann","Billy"), "pets": None, "cars": [ {"model": "BMW 230", "mpg": 27.5}, {"model": "Ford Edge", "mpg": 24.1} ] } # use four indents to make it easier to read the result: print(json.dumps(x, indent=4))
You can also define the separators, default value is (“, “, “: “), which means using a comma and a space to separate each object, and a colon and a space to separate keys from values:
Example
Use the separators
parameter to change the default separator:
import json x = { "name": "John", "age": 32, "married": True, "divorced": False, "children": ("Ann","Billy"), "pets": None, "cars": [ {"model": "BMW 230", "mpg": 27.5}, {"model": "Ford Edge", "mpg": 24.1} ] } # use . and a space to separate objects, and a space, a = and a space to separate keys from their values: print(json.dumps(x, indent=4, separators=(". ", " = ")))
Order the Result
The json.dumps()
method has parameters to order the keys in the result:
Example
Use the sort_keys
parameter to specify if the result should be sorted or not:
import json x = { "name": "John", "age": 32, "married": True, "divorced": False, "children": ("Ann","Billy"), "pets": None, "cars": [ {"model": "BMW 230", "mpg": 27.5}, {"model": "Ford Edge", "mpg": 24.1} ] } # sort the result alphabetically by keys: print(json.dumps(x, indent=4, sort_keys=True))