[Solved] Given this code snippet, what will be printed when a new User instance is saved? from django.db.models.... Given this code snippet, what will be printed when a new User instance is saved? | Django

Django - Signals

Given this code snippet, what will be printed when a new User instance is saved?

from django.db.models.signals import post_save
from django.dispatch import receiver

@receiver(post_save, sender=User)
def user_saved(sender, instance, created, **kwargs):
    if created:
        print(f"User {instance.username} created")
    else:
        print(f"User {instance.username} updated")

user = User(username='alice')
user.save()

AUser alice updated

BUser alice created

CNo output

DError: receiver not connected

Step-by-Step Solution

Solution:

Step 1: Understand the post_save signal and receiver
The receiver listens for post_save on User. It prints 'created' if the instance is new.
Step 2: Analyze the save call
Creating a new User and calling save triggers post_save with created=True, so it prints 'User alice created'.
Final Answer:
User alice created -> Option B
Quick Check:
New save triggers created=True message [OK]

Quick Trick: post_save with created=True means new instance saved [OK]

Common Mistakes:

MISTAKES

Assuming updated message prints on new save
Thinking receiver is not connected automatically
Ignoring the created flag in the receiver

Master "Signals" in Django

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Perf

More Django Quizzes

Given this code snippet, what will be printed when a new User instance is saved?

Step 1: Understand the post_save signal and receiver

Step 2: Analyze the save call

Final Answer:

Quick Check:

Want More Practice?