add error for prefixed non multi units

andrewgsavage · May 27, 2024 · 11a9c6d · 11a9c6d
1 parent 9972e60
commit 11a9c6d
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
@@ -60,7 +60,7 @@
     UnitLike,
 )
 from ...compat import Self, TypeAlias, deprecated
-from ...errors import DimensionalityError, RedefinitionError, UndefinedUnitError
+from ...errors import DimensionalityError, RedefinitionError, UndefinedUnitError, OffsetUnitCalculusError
 from ...pint_eval import build_eval_tree
 from ...util import (
     ParserHelper,
@@ -664,6 +664,9 @@ def get_name(self, name_or_alias: str, case_sensitive: bool | None = None) -> st
             )
 
         if prefix:
+            if not self._units[unit_name].is_multiplicative:
+                raise OffsetUnitCalculusError("Prefixing a unit requires multiplying the unit.")
+
             name = prefix + unit_name
             symbol = self.get_symbol(name, case_sensitive)
             prefix_def = self._prefixes[prefix]