add a new method that counts the number of occurrences

jci/admin.py

@@ -8,7 +8,7 @@ class InlineStandard(admin.StackedInline):
 
 
 class ChapterAdmin(admin.ModelAdmin):
-    list_display = ('__str__', 'acronym')
+    list_display = ('__str__', 'acronym', 'number_of_associated_standards')
     list_filter = ('section',)
     inlines = [InlineStandard]
 

jci/models.py

@@ -19,7 +19,15 @@ class Chapter(models.Model):
 
     def __str__(self):
         return '{} - {}'.format(self.acronym, self.name)
-       
+
+    def number_of_associated_standards(self):
+        """Returns the number of standards that are associated to the current chapter.
+
+        Returns:
+            An integer that counts the number of associated standards.
+        """
+        return Standard.objects.filter(headline=self).count()
+
     class Meta:
         ordering = ('name',)