How to pretty print JSON file

Pretty printing a JSON file in python is easy. Python provides a module called JSON to deal with JSON files. This module provides a lot of useful method including a method called dumps to pretty print JSON content.

In this post, I will show you how to pretty print JSON data in python with examples.

Example to pretty print :

Let’s consider the below example :

import json

data = '[{"name" : "Alex", "age" : 19},{"name" : "Bob", "age" : 18},{"name" : "Charlie", "age" : 21}]'

json_obj = json.loads(data)

pretty_obj = json.dumps(json_obj)

print(pretty_obj)

Here, data is the given JSON. json.loads converts the JSON data to a JSON object. We are using json.dumps to convert that JSON object. If you execute this program, it will give one output as like below :

Not a pretty print ! Because we need to specify the indent level in the dumps method :

pretty_obj = json.dumps(json_obj, indent=4)

Not it will give the required result :

Read JSON file and pretty print data :

Create one new file example.json and put the below JSON data :

[{"name" : "Alex", "age" : 19},{"name" : "Bob", "age" : 18},{"name" : "Charlie", "age" : 21}]'

In the same folder, create one python file to read the contents from this file :

import json

with open('example.json', 'r') as example_file:
    json_obj = json.load(example_file)

pretty_obj = json.dumps(json_obj, indent=4)

print(pretty_obj)

Note that we are using load(), not loads() to read the content from a file. It will pretty print the file data.

Write pretty print JSON data to a file :

We can also use the above method to pretty print data to a separate file.

import json

data = '[{"name" : "Alex", "age" : 19},{"name" : "Bob", "age" : 18},{"name" : "Charlie", "age" : 21}]'
example_file = open('example.json', 'w');

json_obj = json.loads(data)
pretty_obj = json.dumps(json_obj, indent=4)

example_file.write(pretty_obj)
example_file.close()

If you open the example.json file, it will looks as like below :

Reference :

Python doc