new_contents: #http://stackoverflow.com/a/8094563
  
  class MyModel(models.Model):
      onefield = models.CharField('The field', max_length=100)
  
  class MyModelAdmin(admin.ModelAdmin):
    def has_add_permission(self, request):
      # if there's already an entry, do not allow adding
      count = MyModel.objects.all().count()
      if count == 0:
        return True
  
      return False
      
      
  #--------------------------------
  #appereance/models.py
  class Data_Toko(models.Model):
  	nama_toko = models.CharField(max_length=200, .... )
  	nama_kontak = models.CharField(max_length=200, .... )
  	nomor_hp = models.CharField(max_length=200, .... )
  	email_kontak = models.EmailField(max_length=70, .... )
  	pin_bb = models.CharField(max_length=200, .... )
  	jam_kerja = models.CharField(max_length=200, .... )
  	ym = models.CharField(max_length=200, ... )
  	kode_pos = models.CharField(max_length=200, .... )
  	alamat_toko = models.TextField(blank=True, .... )
  
  #appereance/admin.py
  class AdminData_Toko(admin.ModelAdmin):
  	def has_add_permission(self, request):
  		count = models.Data_Toko.objects.all().count()
  		if count == 0:
  			return True
  		return False
  	inlines = [ Data_BankInline, PengirimanInline ]
  	#http://stackoverflow.com/a/1744292
  	formfield_overrides = {
          base_model.TextField: {'widget': Textarea(attrs={'rows': 5, 'cols': 82,})},
      }
  
subject: Create limit-single-record.py