old_contents: from django.contrib import admin
  
  from classes.models import Attendee
  from classes.models import Attendance
  from classes.models import Session
  from classes.models import WalkinClass
  
  
  class AttendanceInline(admin.TabularInline):
      model = Attendance
      extra = 1
      verbose_name = 'Attendee'
      verbose_name_plural = 'Attendees'
      fields = ('attendee', 'start_date_time', "stop_date_time", 'notes')
      # fieldsets = (
      #     ("Attendee", {'fields': ('name'),}),
      #     ("Start Date Time", {"fields": ('start_date_time'),}),
      #     ("Stop Date Time", {"fields": ('stop_date_time'),}),
      #     ('Notes', {'fields': ('notes'),}),
      # )
  
  
  class AttendeeAdmin(admin.ModelAdmin):
      pass
  
  
  class SessionAdmin(admin.ModelAdmin):
      inlines = [
          AttendanceInline,
      ]
      fields = ('walk_in_class','teacher', 'start_date_time', "stop_date_time", )
      list_display= ('walk_in_class', 'start_date_time',)
  
  class WalkinClassAdmin(admin.ModelAdmin):
      pass
  
  admin.site.register(Attendee, AttendeeAdmin)
  admin.site.register(Session, SessionAdmin)
  admin.site.register(WalkinClass, WalkinClassAdmin)
  
new_contents: from django.contrib import admin
  
  from classes.models import Attendee
  from classes.models import Attendance
  from classes.models import Session
  from classes.models import WalkinClass
  
  
  class AttendanceInline(admin.TabularInline):
      model = Attendance
      extra = 1
      verbose_name = 'Attendee'
      verbose_name_plural = 'Attendees'
      fields = ('attendee', 'start_date_time', "stop_date_time", 'notes')
  
  
  class SessionInline(admin.TabularInline):
      model = Session
      extra = 1
      fields = ('start_date_time', 'stop_date_time', 'teacher')
  
  
  class AttendeeAdmin(admin.ModelAdmin):
      pass
  
  
  class SessionAdmin(admin.ModelAdmin):
      inlines = [
          AttendanceInline,
      ]
      fields = ('walk_in_class','teacher', 'start_date_time', "stop_date_time", )
      list_display= ('walk_in_class', 'start_date_time',)
  
  class WalkinClassAdmin(admin.ModelAdmin):
      inlines = [
          SessionInline,
      ]
  
  admin.site.register(Attendee, AttendeeAdmin)
  admin.site.register(Session, SessionAdmin)
  admin.site.register(WalkinClass, WalkinClassAdmin)
  
subject: Add sessions inline to classes