--- a/data_schema/__init__.py	Fri Jul 07 02:17:45 2023 +0200
+++ b/data_schema/__init__.py	Fri Jul 07 02:33:28 2023 +0200
@@ -20,8 +20,8 @@
 
 __date__ = "|VCSJustDate|"
 
-__all__ = ["ERROR", "WARNING", "INFO", "ERRORS", "WARNINGS",
-           "level_name", "problem_message",
+__all__ = ["SEVERITY", "ERRORS", "WARNINGS",
+           "problem_message",
            "ValidationProblem", "SchemaError",
            "validate",
            "log_problem_cause"]
@@ -47,16 +47,11 @@
     return msg
 
 
-ERROR = 40
-WARNING = 30
-INFO = 20
-
-_level_to_name = {
-    ERROR: "ERROR",
-    WARNING: "WARNING",
-    INFO: "INFO",
-}
-_name_to_level = {name: level for (level, name) in _level_to_name.items()}
+@enum.unique
+class SEVERITY(enum.IntEnum):
+    INFO = 20
+    WARNING = 30
+    ERROR = 40
 
 
 @enum.unique
@@ -150,13 +145,6 @@
 """URI path to the current schema"""
 
 
-def level_name(level):
-    name = _level_to_name.get(level)
-    if name is None:
-        name = "Level {}".format(level)
-    return name
-
-
 def problem_message(pr):
     if isinstance(pr, ValidationProblem):
         code = getattr(pr, "code", None)
@@ -191,12 +179,14 @@
         if severity is None:
             # autodetermine
             if code in ERRORS:
-                self.severity = ERROR
+                self.severity = SEVERITY.ERROR
             elif code in WARNINGS:
-                self.severity = WARNING
+                self.severity = SEVERITY.WARNING
             else:
                 assert False
         else:
+            if not isinstance(severity, SEVERITY):
+                raise TypeError("invalid type for `severity'")
             self.severity = severity
         self.hint = hint
         self.context = context
@@ -216,11 +206,11 @@
         except LookupError:
             msg = ""
         if self.index is None:
-            return "ValidationProblem(code={}{}, severity={!r}, hint={}, context=[depth={}]{})".format(
-                self.code.name, msg, self.severity, self.hint, self.context.depth, self.context)
+            return "ValidationProblem(code={}{}, severity={}, hint={}, context=[depth={}]{})".format(
+                self.code.name, msg, self.severity.name, self.hint, self.context.depth, self.context)
         else:
-            return "ValidationProblem(code={}{}, severity={!r}, hint={}, context=[depth={}]{}, index={})".format(
-                self.code.name, msg, self.severity, self.hint, self.context.depth, self.context, self.index)
+            return "ValidationProblem(code={}{}, severity={}, hint={}, context=[depth={}]{}, index={})".format(
+                self.code.name, msg, self.severity.name, self.hint, self.context.depth, self.context, self.index)
 
 
 class SchemaError(Exception):