old_contents: from mapfeed.models import MapPath, MapCity, MapLine, MapStation, Incident
  from django.contrib import admin
  
  admin.site.register(MapCity)
  admin.site.register(MapLine)
  admin.site.register(MapPath)
  admin.site.register(MapStation)
  admin.site.register(Incident)
  
new_contents: from mapfeed.models import MapPath, MapCity, MapLine, MapStation, Incident
  from django.contrib import admin
  
  class MapCityAdmin(admin.ModelAdmin):
      list_display = ('city_name', 'rail_name')
  
  class MapLineAdmin(admin.ModelAdmin):
      list_display = ('line_name', 'line_code')
  
  class MapPathAdmin(admin.ModelAdmin):
      pass
  
  class MapStationAdmin(admin.ModelAdmin):
      list_display = ('station_name', 'station_code')
  
  class IncidentAdmin(admin.ModelAdmin):
      pass
  
  admin.site.register(MapCity, MapCityAdmin)
  admin.site.register(MapLine, MapLineAdmin)
  admin.site.register(MapPath, MapPathAdmin)
  admin.site.register(MapStation, MapStationAdmin)
  admin.site.register(Incident, IncidentAdmin)
  
subject: add list columns to admin site