Sets default value for district corporation field

stages/admin.py

@@ -215,13 +215,21 @@ class ContactInline(admin.StackedInline):
 
 
 class CorporationAdmin(admin.ModelAdmin):
-    list_display = ('name', 'short_name', 'pcode', 'city', 'ext_id')
+    list_display = ('name', 'short_name', 'pcode', 'city', 'district', 'ext_id')
     list_editable = ('short_name',)  # Temporarily?
     list_filter = (('archived', ArchivedListFilter),)
     search_fields = ('name', 'street', 'pcode', 'city')
     ordering = ('name',)
-    fields = (('name', 'short_name'), 'parent', ('sector', 'typ', 'ext_id'),
-              'street', ('pcode', 'city'), ('tel', 'email'), 'web', 'archived')
+    fields = (
+        ('name', 'short_name'),
+        'parent',
+        ('sector', 'typ', 'ext_id'),
+        'street',
+        ('pcode', 'city', 'district'),
+        ('tel', 'email'),
+        'web',
+        'archived',
+    )
     inlines = [ContactInline]
 
     def get_search_results(self, request, qs, term):

stages/migrations/0016_populate_corp_district.py

@@ -0,0 +1,26 @@
+from django.db import migrations
+
+
+def populate_district(apps, schema_editor):
+    Corporation = apps.get_model('stages', 'Corporation')
+
+    for corp in Corporation.objects.filter(district=''):
+        pcode = int(corp.pcode)
+        if pcode in range(2000, 2334) or pcode in range(2400, 2417) or pcode in [2523, 2525, 2616]:
+            corp.district = 'NE'
+            corp.save()
+        elif pcode in range(2336, 2365) or pcode in range(2714, 2719) or pcode in range(2800, 2955):
+            corp.district = 'JU'
+            corp.save()
+        elif pcode in [2333, 2346] or pcode in range(2500, 2521) or pcode in range(2532, 2763) or pcode in range(3000, 3865):
+            corp.district = 'BE'
+            corp.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stages', '0015_added_supervision_attest_field'),
+    ]
+
+    operations = [migrations.RunPython(populate_district)]