wrote code for models and admin pages

javing_reading/bookshelf/admin.py

 from django.contrib import admin
-
+from .models import Author, Book
 # Register your models here.
+
+# show books in page for authors
+class BookInline(admin.TabularInline):
+    model = Book
+
+class AuthorAdmin(admin.ModelAdmin):
+    model = Author
+    list_display = ("first_name", "last_name", "age", "nationality")
+    search_fields = ("first_name", "last_name")
+    list_filter = ("nationality")
+
+    inlines = [BookInline]
+
+class BookAdmin(admin.ModelAdmin):
+    list_display = ("title", "get_author", "year_published", "ISBN")
+    list_filter = ("get_author", "publisher")
+
+    def get_author(self, obj):
+        return obj.author.title
+    
+    # title of column for get_author
+    get_author.short_description = "Author"
+
+    # sorting by Author
+    get_author.admin_order_field = "Author"
+
+admin.site.register(Author, AuthorAdmin)
+admin.site.register(Book, BookAdmin)
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javing_reading/bookshelf/models.py

 from django.db import models
 
 # Create your models here.
+class Author (models.Model):
+    first_name = models.CharField(max_length = 50)
+    last_name = models.CharField(max_length = 30)
+
+    age = models.IntegerField(default = 10)
+    nationality = models.CharField(max_length = 50)
+    
+    bio = models.TextField(max_length = 700)
+
+class Book (models.Model):
+    title = models.CharField(max_length = 50)
+    author = models.ForeignKey(Author, on_delete = models.CASCADE)
+
+    publisher = models.CharField(max_length = 100)
+    year_published = models.IntegerField(default = 1984)
+
+    ISBN = models.IntegerField(
+        max_value = 9999999999999, 
+        min_value = 1000000000000
+    )
+    blurb = models.TextField(min_length = 100, max_length = 200)
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