Convert JSON to Python Object (Non Nested, Nested & Multiple Object)

This article explains how to convert JSON data to Python native object for different cases.

Converting JSON data to native Python object is quite useful when you're dealing with data obtained from API or JSON data loaded from file.

To convert JSON data to Python object, there are different methods. In this article, we create simple class to do it and use @staticmethod decorator. This is the most effective way to do it. You can use @classmethod as well with small modification.

Starting from non nested single object case, we cover non nested multiple object & nested multiple object to clear the concept.

Non-nested Simple Case

Suppose you have following JSON data in file named single_student.json:

{
    "student_id": "BCE001",
    "department": "Civil",
    "name": "Anisha Dahal",
    "email": "anisha@email.com"
}

Python Source Code

import json

class Student:
    def __init__(self,student_id, department, name, email):
        self.student_id = student_id
        self.department = department
        self.name = name
        self.email = email
    
    @staticmethod
    def create_from_json(data):
        json_dictionary = json.loads(data)
        return Student(**json_dictionary)
    
    def __str__(self):
        return "<Student {0}>".format(self.name)


with open("single_student.json","r") as json_data:
    student_json = json_data.read()
    print("Json object read from file:")
    print("------------------------------")
    print(student_json)
    print("\nConverted Python object & detail:")
    print("------------------------------")
    student_python = Student.create_from_json(student_json)
    print(student_python)
    print("student_id:", student_python.student_id)
    print("department:", student_python.department)
    print("name:", student_python.name)
    print("email:", student_python.email)

Output

Json object read from file:
------------------------------
{
    "student_id": "BCE001",
    "department": "Civil",
    "name": "Anisha Dahal",
    "email": "anisha@email.com"
}

Converted Python object & detail:
------------------------------
<Student Anisha Dahal>
student_id: BCE001
department: Civil
name: Anisha Dahal
email: anisha@email.com

Non-nested & Multiple Object

Suppose you have following JSON data with multiple objects in file named student.json:

[
    {
        "student_id": "BCE001",
        "department": "Civil",
        "name": "Anisha Dahal",
        "email": "anisha@email.com"
    },
    
    {
        "student_id": "BEL002",
        "department": "Electrical",
        "name": "Manisha Adhikari",
        "email": "manisha@email.com"
    },
    
    {
        "student_id": "BEX003",
        "department": "Electronics",
        "name": "Sreeja Poudel",
        "email": "sreeja@email.com"
    },
    
    {
        "student_id": "BCT004",
        "department": "Computer",
        "name": "Srishaa Sundas",
        "email": "srishaa@email.com"
    }
]

Python Source Code

import json

class Student:
    def __init__(self,student_id, department, name, email):
        self.student_id = student_id
        self.department = department
        self.name = name
        self.email = email
    
    @staticmethod
    def create_from_json(data):
        json_dictionary = json.loads(data)
        return Student(**json_dictionary)
    
    def __str__(self):
        return "<Student {0}>".format(self.name)

# Test
student_python = []

with open("student.json", "r") as json_data:
    student_json = json.loads(json_data.read())
    
    for student in student_json:
        student_python.append(Student(**student))

# Displaying student from python object
for student in student_python:
    print('Python Object:', student)

Output

Python Object: <Student Anisha Dahal>
Python Object: <Student Manisha Adhikari>
Python Object: <Student Sreeja Poudel>
Python Object: <Student Srishaa Sundas>

Nested & Multiple Object

Suppose you have following Nested JSON data in file named nested_student.json:

[
    {
        "student_id": "BCE001",
        "department": "Civil",
        "name": {
            "first": "Anisha",
            "last": "Dahal"
        },
        "email": "anisha@email.com"
    },
    
    {
        "student_id": "BCE002",
        "department": "Electrical",
        "name": {
            "first": "Manisha",
            "last": "Adhikari"
        },
        "email": "manisha@email.com"
    },
    
    {
        "student_id": "BCE003",
        "department": "Electronics",
        "name": {
            "first": "Sreeja",
            "last": "Poudel"
        },
        "email": "sreeja@email.com"
    },
    
    {
        "student_id": "BCE004",
        "department": "Computer",
        "name": {
            "first": "Srishaa",
            "last": "Sundas"
        },
        "email": "srishaa@email.com"
    }
]

Python Source Code

import json

class Student:
    def __init__(self,student_id, department, name, email):
        self.student_id = student_id
        self.department = department
        self.first_name = name['first']
        self.last_name = name['last']
        self.email = email
    
    @staticmethod
    def create_from_json(data):
        json_dictionary = json.loads(data)
        return Student(**json_dictionary)
    
    def __str__(self):
        return "<Student {0}>".format(self.first_name)

# Test
student_python = []

with open("nested_student.json", "r") as json_data:
    student_json = json.loads(json_data.read())
    
    for student in student_json:
        student_python.append(Student(**student))

# Displaying student from python object
print("\n\nAll student python objects")
print("------------------------------")
for student in student_python:
    print('Python Object:', student)

# Detail of first student
print("\n\nDetail of first student")
print("------------------------------")
print("student_id:", student_python[0].student_id)
print("department:", student_python[0].department)
print("first name:", student_python[0].first_name)
print("last name:", student_python[0].last_name)
print("email:", student_python[0].email)

Output

All student python objects
------------------------------
Python Object: <Student Anisha>
Python Object: <Student Manisha>
Python Object: <Student Sreeja>
Python Object: <Student Srishaa>


Detail of first student
------------------------------
student_id: BCE001
department: Civil
first name: Anisha
last name: Dahal
email: anisha@email.com

Using @classmethod

If you're using @classmethod decorator then function definition for create_from_json() will be:

@classmethod
def create_from_json(cls,data):
    json_dictionary = json.loads(data)
    return cls(**json_dictionary)