Adds data migration for converting units to valid values

InvenTree/part/migrations/0109_auto_20230517_1048.py

@@ -22,7 +22,7 @@ def update_template_units(apps, schema_editor):
     ureg = InvenTree.conversion.get_unit_registry()
 
     n_converted = 0
-    invalid_units = []
+    invalid_units = set()
 
     for template in PartParameterTemplate.objects.all():
 
@@ -69,8 +69,8 @@ def update_template_units(apps, schema_editor):
                 break
 
         if not found:
-            print(f"warningCould not find unit match for {template.units}")
+            print(f"warning: Could not find unit match for {template.units}")
-            invalid_units.append(template.units)
+            invalid_units.add(template.units)
 
     print(f"Updated units for {n_templates} parameter templates")
 

InvenTree/part/migrations/0111_auto_20230521_1350.py

@@ -0,0 +1,89 @@
+# Generated by Django 3.2.19 on 2023-05-21 13:50
+
+import pint
+
+from django.core.exceptions import ValidationError
+from django.db import migrations
+
+import InvenTree.conversion
+
+
+def migrate_part_units(apps, schema_editor):
+    """Update the units field for each Part object:
+
+    - Check if the units are valid
+    - Attempt to convert to valid units (if possible)
+    """
+
+    Part = apps.get_model('part', 'Part')
+
+    parts = Part.objects.exclude(units=None).exclude(units='')
+    n_parts = parts.count()
+
+    ureg = InvenTree.conversion.get_unit_registry()
+
+    invalid_units = set()
+    n_converted = 0
+
+    for part in parts:
+
+        # Override '%' units (which are invalid)
+        if part.units == '%':
+            part.units = 'percent'
+            part.save()
+            continue
+
+        # Test if unit is 'valid'
+        try:
+            ureg.Unit(part.units)
+            continue
+        except pint.errors.UndefinedUnitError:
+            pass
+
+        # Check a lower-case version
+        try:
+            ureg.Unit(part.units.lower())
+            print(f"Found unit match: {part.units} -> {part.units.lower()}")
+            part.units = part.units.lower()
+            part.save()
+            n_converted += 1
+            continue
+        except pint.errors.UndefinedUnitError:
+            pass
+
+        found = False
+
+        # Attempt to convert to a valid unit
+        for unit in ureg:
+            if unit.lower() == part.units.lower():
+                print("Found unit match: {part.units} -> {unit}")
+                part.units = str(unit)
+                part.save()
+                n_converted += 1
+                found = True
+                break
+
+        if not found:
+            print(f"Warning: Invalid units for part '{part}': {part.units}")
+            invalid_units.add(part.units)
+
+    print(f"Updated units for {n_parts} parts")
+
+    if n_converted > 0:
+        print(f"Converted units for {n_converted} parts")
+
+    if len(invalid_units) > 0:
+        print(f"Found {len(invalid_units)} invalid units:")
+        for unit in invalid_units:
+            print(f" - {unit}")
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0110_alter_part_units'),
+    ]
+
+    operations = [
+        migrations.RunPython(code=migrate_part_units, reverse_code=migrations.RunPython.noop)
+    ]