reafctor(arch): cap puid length to 20

arch/migrations/0032_alter_problem_puid.py

@@ -0,0 +1,29 @@
+# Generated by Django 4.1.10 on 2023-08-08 01:44
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("arch", "0031_vote_created_at_vote_updated_at"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="problem",
+            name="puid",
+            field=models.CharField(
+                help_text="Problem identifier, as printed in OTIS. Capital letters and digits only.",
+                max_length=20,
+                unique=True,
+                validators=[
+                    django.core.validators.RegexValidator(
+                        message="Only uppercase letters and digits appear in PUID's.",
+                        regex="^[A-Z0-9]+$",
+                    )
+                ],
+                verbose_name="PUID",
+            ),
+        ),
+    ]

arch/models.py

@@ -25,7 +25,7 @@ def get_disk_statement_from_puid(puid: str) -> Optional[str]:
 @reversion.register()
 class Problem(models.Model):
     puid = models.CharField(
-        max_length=24,
+        max_length=20,
         help_text="Problem identifier, as printed in OTIS. Capital letters and digits only.",
         unique=True,
         verbose_name="PUID",