Creating objects in Python - Visual Walkthrough

Concept Flow - Creating objects

Define class

↓

Create object

↓

Call __init__ method

↓

Object initialized

↓

Use object attributes/methods

This flow shows how a class is defined, then an object is created which calls the __init__ method to set up the object, making it ready to use.

Execution Sample

Python

class Dog:
    def __init__(self, name):
        self.name = name

my_dog = Dog("Buddy")
print(my_dog.name)

This code defines a Dog class, creates a Dog object named Buddy, and prints its name.

Execution Table

Step	Action	Evaluation	Result
1	Define class Dog	Class Dog created	Dog class ready
2	Create object my_dog = Dog("Buddy")	Call __init__ with name='Buddy'	my_dog object created
3	Inside __init__: self.name = 'Buddy'	Assign attribute	my_dog.name set to 'Buddy'
4	print(my_dog.name)	Access attribute	Output: Buddy
5	End of program	No more code	Program stops

💡 Program ends after printing the object's name.

Variable Tracker

Variable	Start	After Step 2	After Step 3	Final
my_dog	None	Object created	Object with name='Buddy'	Object with name='Buddy'

Key Moments - 2 Insights

Why do we use self.name inside __init__ instead of just name?

self.name stores the value in the object itself, so it can be used later. The execution_table step 3 shows self.name is assigned, linking the name to the object.

What happens when we write my_dog = Dog("Buddy")?

It creates a new Dog object and calls __init__ to set it up. See execution_table step 2 and 3 where the object is created and initialized.

Visual Quiz - 3 Questions

Look at the execution_table, what is the output at step 4?

A "my_dog"

B "Buddy"

C Error

D "Dog"

💡 Hint

Check the 'Result' column at step 4 in the execution_table.

At which step is the attribute 'name' assigned to the object?

A Step 3

B Step 2

C Step 1

D Step 4

💡 Hint

Look at the 'Action' column describing attribute assignment in the execution_table.

If we create another Dog object with Dog("Max"), what changes in variable_tracker?

A No change in variable_tracker

B The existing my_dog row changes name to 'Max'

C A new row for the new object appears

D The Start value changes to 'Max'

💡 Hint

Each object is tracked separately; variable_tracker shows one object per row.

Concept Snapshot

class ClassName:
    def __init__(self, params):
        self.attribute = value

obj = ClassName(args)  # creates object
print(obj.attribute)   # access attribute

Key: self links attributes to the object.

Full Transcript

This example shows how to create objects in Python. First, we define a class named Dog with an __init__ method that sets the name attribute. When we create an object my_dog with Dog("Buddy"), Python calls __init__ to assign the name 'Buddy' to the object. Finally, printing my_dog.name outputs 'Buddy'. The variable tracker shows how my_dog changes from None to an object with the name attribute. Key points include using self to store attributes and how object creation calls __init__ automatically.