My models **`Book`** and **`ReadList`** related and I can use them on Django Admin but I want to fetch **`bookPageCount`** field of selected object and save it to **`pageCount`** field of new object when save.

```py
from django.db import models
from django.db.models.signals import post_save, pre_save
from django.dispatch import receiver

# Create your models here.

class Book(models.Model):
    bookname = models.CharField(max_length=200, verbose_name='Kitap Adı')
    bookAuthor = models.CharField(max_length=100, verbose_name='Yazar Adı')
    bookPublisher = models.CharField(max_length=100, verbose_name='Yayın Evi')
    bookPageCount = models.PositiveIntegerField(verbose_name='Sayfa Sayısı')
    bookAddDate = models.DateField(verbose_name='Kitaplığa Eklenme Tarihi')
    class Meta:
        verbose_name = 'Kitap'
        verbose_name_plural = 'Kitaplar'
    def __str__(self):
        return self.bookname

class ReadList(models.Model):
    bookName = models.ForeignKey('kitaplik.Book', related_name='book', on_delete=models.CASCADE, verbose_name='Kitap Adı')
    readerName = models.ForeignKey('ogrenciler.Students', on_delete=models.CASCADE, related_name='readerName', verbose_name='Okuyan Kişi')
    dateOfRead = models.DateField(verbose_name='Okuma Tarihi')
    pageCount = models.PositiveIntegerField(verbose_name='Sayfa Sayısı',blank=True, null=True)
    class Meta:
        verbose_name = 'Okuma Günlüğü'

@receiver(post_save, sender=ReadList)
def get_pageCount(sender, instance, **kwargs):
    instance.pageCount = instance.Book.bookPageCount
    instance.save

```

**EDIT**: Changes been made after Higor's reminder but I still have problem as the same. The error I get is `'ReadList' object has no attribute 'Book'`