fix(python): validate map values (not keys) for additionalProperties.enum

src/main/resources/handlebars/python/model.mustache

@@ -129,10 +129,10 @@ class {{classname}}({{#parent}}{{parent}}{{/parent}}{{^parent}}object{{/parent}}
             )
 {{/isListContainer}}
 {{#isMapContainer}}
-        if not set({{{name}}}.keys()).issubset(set(allowed_values)):
+        if not set({{{name}}}.values()).issubset(set(allowed_values)):
             raise ValueError(
-                "Invalid keys in `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
-                .format(", ".join(map(str, set({{{name}}}.keys()) - set(allowed_values))),  # noqa: E501
+                "Invalid values in `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
+                .format(", ".join(map(str, set({{{name}}}.values()) - set(allowed_values))),  # noqa: E501
                         ", ".join(map(str, allowed_values)))
             )
 {{/isMapContainer}}

src/main/resources/handlebars/pythonFlaskConnexion/model.mustache

@@ -99,10 +99,10 @@ class {{classname}}(Model):
             )
 {{/isListContainer}}
 {{#isMapContainer}}
-        if not set({{{name}}}.keys()).issubset(set(allowed_values)):
+        if not set({{{name}}}.values()).issubset(set(allowed_values)):
             raise ValueError(
-                "Invalid keys in `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
-                .format(", ".join(map(str, set({{{name}}}.keys()) - set(allowed_values))),  # noqa: E501
+                "Invalid values in `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
+                .format(", ".join(map(str, set({{{name}}}.values()) - set(allowed_values))),  # noqa: E501
                         ", ".join(map(str, allowed_values)))
             )
 {{/isMapContainer}}

src/test/java/io/swagger/codegen/v3/generators/python/PythonMapEnumValidationTest.java

@@ -0,0 +1,60 @@
+package io.swagger.codegen.v3.generators.python;
+
+import io.swagger.codegen.v3.generators.GeneratorRunner;
+import io.swagger.codegen.v3.service.GenerationRequest;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.List;
+
+/**
+ * Regression test for the Python generator `Map<String, Enum>` setter validation.
+ *
+ * <p>The {@code model.mustache} template used to emit
+ * {@code set(x.keys()).issubset(allowed_values)} for properties declared as
+ * {@code type: object} with {@code additionalProperties.enum}. Per OpenAPI 3.0
+ * semantics, {@code additionalProperties} describes map values, so the enum
+ * constraint applies to the values, not the keys. The fix validates
+ * {@code set(x.values()).issubset(allowed_values)} and updates the error message
+ * from "Invalid keys in" to "Invalid values in".
+ */
+public class PythonMapEnumValidationTest {
+
+    @Test
+    public void mapOfEnumSetterValidatesValuesNotKeys() throws Exception {
+        final List<File> files = GeneratorRunner.runGenerator(
+            "python",
+            "3_0_0/map_of_inner_enum.yaml",
+            GenerationRequest.CodegenVersion.V3,
+            false,
+            true,
+            true,
+            null,
+            options -> {});
+
+        Assert.assertFalse(files.isEmpty());
+
+        final File modelFile = files.stream()
+            .filter(f -> f.getName().equals("employee_with_map_of_enum.py"))
+            .findFirst()
+            .orElseThrow(() -> new RuntimeException("employee_with_map_of_enum.py was not generated"));
+
+        final String content = new String(Files.readAllBytes(Paths.get(modelFile.toURI())));
+
+        Assert.assertTrue(
+            content.contains("set(project_role.values()).issubset(set(allowed_values))"),
+            "Setter should validate map values (not keys) against the enum.\nGenerated:\n" + content);
+        Assert.assertTrue(
+            content.contains("Invalid values in `project_role`"),
+            "Setter error message should reference 'Invalid values in'.\nGenerated:\n" + content);
+        Assert.assertFalse(
+            content.contains("set(project_role.keys()).issubset(set(allowed_values))"),
+            "Setter must not validate map keys against the enum.\nGenerated:\n" + content);
+        Assert.assertFalse(
+            content.contains("Invalid keys in `project_role`"),
+            "Setter error message must not reference 'Invalid keys in'.\nGenerated:\n" + content);
+    }
+}