How To Return An Instance Of A Class Python

In this tutorial, we will learn how to return an instance of a class in Python. Returning an instance of a class is a common practice in object-oriented programming (OOP) to create and manipulate objects. This tutorial will guide you through creating a simple class and how to return its instances using methods.

Step 1: Create a Class

First, let’s create a simple class called Student with an __init__() method that initializes the attributes name and age.

1
2
3
4
class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age

Step 2: Create a Method to Return an Instance of the Class

Now, let’s create a method called create_student() inside the class that takes the name and age as arguments and returns an instance of the Student class with these attributes.

1
2
3
4
5
6
7
8
class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age
 
    @classmethod
    def create_student(cls, name, age):
        return cls(name, age)

Notice the @classmethod decorator above the create_student() method. This decorator lets us define a method as a class method. A class method takes a reference to the class itself as its first argument, typically named cls. Since a class method only has access to the class itself, it can be used to create and return a new instance of the class.

Step 3: Creating and Manipulating Instances of the Class

Now that we have our class with the create_student() method, we can create instances of the Student class and manipulate their attributes. For example, let’s create an instance of the Student class and display its name and age attributes.

1
2
3
4
5
# Create a new Student instance
new_student = Student.create_student("John Doe", 20)
 
# Print the new student's name and age
print(f"Name: {new_student.name}, Age: {new_student.age}")

Output:

Name: John Doe, Age: 20

Full Code

1
2
3
4
5
6
7
8
9
10
11
12
13
14
class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age
 
    @classmethod
    def create_student(cls, name, age):
        return cls(name, age)
 
# Create a new Student instance
new_student = Student.create_student("John Doe", 20)
 
# Print the new student's name and age
print(f"Name: {new_student.name}, Age: {new_student.age}")

Conclusion

In this tutorial, we learned how to return an instance of a class in Python using a class method. This is a useful technique in OOP for creating and manipulating objects. Now, you can implement this technique in your Python projects to utilize the power of OOP.