Python Program to Form a Dictionary from an Object of a Class

When working with classes in Python, you often need to convert an object's attributes into a dictionary format. Python provides the __dict__ attribute that automatically creates a dictionary containing all instance attributes of an object.

Basic Example

Here's how to create a dictionary from a class object using the __dict__ attribute ?

class BaseClass:
    def __init__(self):
        self.A = 32
        self.B = 60

my_instance = BaseClass()
print("An instance of the class has been created")
print(my_instance.__dict__)

An instance of the class has been created
{'A': 32, 'B': 60}

Using Constructor Parameters

You can also create a more flexible class that accepts parameters ?

class Student:
    def __init__(self, name, age, grade):
        self.name = name
        self.age = age
        self.grade = grade

student = Student("Alice", 20, "A")
student_dict = student.__dict__
print("Student dictionary:")
print(student_dict)

Student dictionary:
{'name': 'Alice', 'age': 20, 'grade': 'A'}

Using vars() Function

The vars() function provides an alternative way to get the same result ?

class Product:
    def __init__(self, name, price, quantity):
        self.name = name
        self.price = price
        self.quantity = quantity

product = Product("Laptop", 999.99, 5)
product_dict = vars(product)
print("Product dictionary using vars():")
print(product_dict)

Product dictionary using vars():
{'name': 'Laptop', 'price': 999.99, 'quantity': 5}

Comparison

Key Points

• The __dict__ attribute contains all instance variables as key-value pairs
• Both __dict__ and vars() return the same dictionary
• Only instance attributes are included, not class attributes or methods
• The resulting dictionary can be modified independently of the original object

Conclusion

Use obj.__dict__ or vars(obj) to convert any class object into a dictionary. This technique is useful for serialization, debugging, and data processing tasks.