Object lifecycle overview in Python - Step-by-Step Execution

Concept Flow - Object lifecycle overview

Create Object

→Initialize __init__

↓

Use Object

↓

Delete Object

→Call __del__

This flow shows how an object is created, initialized, used, and then deleted in Python.

Execution Sample

Python

class MyObject:
    def __init__(self):
        print('Object created')
    def __del__(self):
        print('Object deleted')
obj = MyObject()
del obj

This code creates an object, prints a message on creation, then deletes it and prints a message on deletion.

Execution Table

Step	Action	Evaluation	Result
1	Create object obj	Calls __init__	Prints 'Object created'
2	Object obj ready	Object exists in memory	No output
3	Delete object obj	Calls __del__	Prints 'Object deleted'
4	Object obj removed	No longer accessible	No output

💡 Object is deleted and memory is freed, lifecycle ends

Variable Tracker

Variable	Start	After Creation	After Deletion
obj	None	Reference to MyObject instance	No reference (deleted)

Key Moments - 3 Insights

Why do we see 'Object created' printed immediately after creating obj?

Because the __init__ method runs right after the object is created, as shown in execution_table step 1.

Does __del__ run immediately when we call del obj?

Yes, __del__ is called when the object is deleted, as shown in execution_table step 3, printing 'Object deleted'.

What happens if we try to use obj after deletion?

The object no longer exists (execution_table step 4), so using obj will cause an error.

Visual Quiz - 3 Questions

Look at the execution_table, what is printed when the object is created?

A 'Object created'

B 'Object deleted'

C Nothing

D 'Object ready'

💡 Hint

See execution_table step 1, the __init__ method prints 'Object created'.

At which step does the object get removed from memory?

A Step 2

B Step 4

C Step 3

D Step 1

💡 Hint

Check execution_table step 4, it shows the object is no longer accessible.

If we remove the del obj line, what changes in the execution_table?

A Step 2 would be missing

B Step 1 would not happen

C Step 3 and 4 would not happen

D All steps remain the same

💡 Hint

Without del obj, __del__ is not called, so steps 3 and 4 do not occur.

Concept Snapshot

Object lifecycle in Python:
1. Creation calls __init__ to initialize.
2. Object is ready to use.
3. Deletion calls __del__ to clean up.
4. Object memory is freed after deletion.
Use del to delete objects explicitly.

Full Transcript

This visual trace shows the lifecycle of a Python object. First, the object is created, triggering the __init__ method which prints 'Object created'. Then the object exists and can be used. When we delete the object using del, the __del__ method runs and prints 'Object deleted'. Finally, the object is removed from memory and cannot be used anymore. Variables track the object's reference before and after creation and deletion. Key moments clarify why __init__ and __del__ run when they do, and what happens if we try to use the object after deletion. The quiz tests understanding of these steps by asking about printed messages and lifecycle stages.