How to Serialize an Object Into JSON in Python

Today, we are going to learn how to serialize an object into JSON in Python. JSON (JavaScript Object Notation) is a lightweight data-interchange format, easy to understand and write, and equally easy for machines to parse and generate. Python has a built-in module named json, which can be used to work with JSON data.

Step 1: Importing the necessary module

Python provides a built-in module named “json” for JSON processing. Before starting, we need to import it. Use the following line of code to import the json module:

1
import json

Step 2: Working with a simple Python object

Let ‘s work with a simple Python object – a dictionary. Below is our Python object:

1
2
3
4
5
6
 
person = {
  "name": "John",
  "age": 30,
  "city": "New York"
}

Step 3: Using json.dumps()

The json.dumps() method can convert a Python object into a JSON string.

1
2
person_json = json.dumps(person)
print(person_json)

This will output:

{
  "name": "John",
  "age": 30,
  "city": "New York"
}

Step 4: Writing JSON to a file

We can also write the JSON data to a file. Let’s write our JSON person object to a file named “person.json”.

1
2
with open('person.json', 'w') as json_file:
  json.dump(person, json_file)

This code writes the JSON object to a file named “person.json”.

We have now covered how to serialize an object into JSON. Following is the full python code used:

Full Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
import json
 
person = {
  "name": "John",
  "age": 30,
  "city": "New York"
}
 
person_json = json.dumps(person)
print(person_json)
 
with open('person.json', 'w') as json_file:
  json.dump(person, json_file)
 
{"name": "John", "age": 30, "city": "New York"}

Conclusion:

In this tutorial, we learned about JSON and how to convert a Python object into a JSON string. This is also known as serializing. The process is quite simple and straightforward. Python’s built-in json module makes it very easy to serialize Python objects into JSON.

The json.dumps() function is particularly useful in this regard. The json.dump() function is used when you want to serialize the Python object into JSON and write it into a file.