old_contents: from django.contrib import admin
  
  from .models import Theater, Play, People, Production, Cast, Crew, Musician, Musical_Number, Production_Company
  # Register your models here.
  
  
  class CastInline(admin.StackedInline):
      fieldsets = [
          (None,                  {'fields': (('character', 'person'),)}),
          ('Optional Details',    {'fields': ('billed_as', ('is_understudy', 'is_alternating'), ('start_year', 'end_year')),
                                   'classes': ('collapse')}
           )
      ]
      model = Cast
      extra = 1
  
  class ProductionAdmin(admin.ModelAdmin):
      fieldsets = [
          (None,      {'fields': ('play', 'theater', ('start_date', 'end_date'))}),
          ('Details', {'fields': ('prod_company', 'notes'),
                       'classes': ('collapse',)}
           ),
      ]
      inlines = [CastInline]
      list_display = ('play', 'theater', 'start_date')
  
  
  
  
  admin.site.register(Theater)
  admin.site.register(Play)
  admin.site.register(People)
  admin.site.register(Production, ProductionAdmin)
  # admin.site.register(Cast)
  admin.site.register(Crew)
  admin.site.register(Musician)
  admin.site.register(Musical_Number)
  admin.site.register(Production_Company)
  
  # admin.site.register(Theater_pictures)
  
  
new_contents: from django.contrib import admin
  
  from .models import Theater, Play, People, Production, Cast, Crew, Musician, Musical_Number, Production_Company
  # Register your models here.
  
  
  class CastInline(admin.StackedInline):
      fieldsets = [
          (None,                  {'fields': (('person','character'),)}),
          ('Optional Details',    {'fields': ('billed_as', ('is_understudy', 'is_alternating'), ('start_year', 'end_year')),
                                   'classes': ('collapse')}
           )
      ]
      model = Cast
      extra = 1
  
  class ProductionAdmin(admin.ModelAdmin):
      fieldsets = [
          (None,      {'fields': ('play', 'theater', ('start_date', 'end_date'))}),
          ('Details', {'fields': ('prod_company', 'notes'),
                       'classes': ('collapse',)}
           ),
      ]
      inlines = [CastInline]
      list_display = ('play', 'theater', 'start_date')
  
  
  
  
  admin.site.register(Theater)
  admin.site.register(Play)
  admin.site.register(People)
  admin.site.register(Production, ProductionAdmin)
  # admin.site.register(Cast)
  admin.site.register(Crew)
  admin.site.register(Musician)
  admin.site.register(Musical_Number)
  admin.site.register(Production_Company)
  
  # admin.site.register(Theater_pictures)
  
  
subject: reformat casts inline