django save another class data while saving a class

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

class FirstModel(models.Model):
    field1 = models.CharField(max_length=255)
    field2 = models.IntegerField()

class SecondModel(models.Model):
    field3 = models.CharField(max_length=255)
    field4 = models.IntegerField()

@receiver(post_save, sender=FirstModel)
def create_second_model(sender, instance, created, kwargs):
    if created:
        SecondModel.objects.create(field3=instance.field1, field4=instance.field2)

In the code above, we have two Django models, FirstModel and SecondModel. The create_second_model function is a signal receiver that gets triggered after a FirstModel instance is saved.

1. The FirstModel has two fields, field1 and field2.
2. The SecondModel has two fields, field3 and field4.
3. The @receiver decorator is used to connect the create_second_model function to the post_save signal of the FirstModel. This means that the function will be called every time a FirstModel instance is saved.
4. In the create_second_model function, we check if the FirstModel instance was just created (created is True). If it was, we create a new SecondModel instance using the values of field1 and field2 from the FirstModel instance. ```