Fix #17754: Convert OpenAPI types to Python types in anyOf/oneOf

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java

@@ -829,6 +829,63 @@ public GeneratorLanguage generatorLanguage() {
         return GeneratorLanguage.PYTHON;
     }
 
+    private String toPythonType(String openApiType) {
+        if (openApiType == null) {
+            return "Any";
+        }
+        if (openApiType.startsWith("array[")) {
+            String innerType = openApiType.substring(6, openApiType.length() - 1);
+            return "List[" + toPythonType(innerType) + "]";
+        }
+        if (openApiType.startsWith("map[")) {
+            String innerType = openApiType.substring(4, openApiType.length() - 1);
+            return "Dict[" + innerType + "]";
+        }
+        switch (openApiType) {
+            case "string":
+                return "str";
+            case "array":
+                return "List";
+            case "object":
+                return "Dict";
+            case "number":
+                return "float";
+            case "integer":
+                return "int";
+            case "boolean":
+                return "bool";
+            case "binary":
+                return "bytes";
+            default:
+                return openApiType;
+        }
+    }
+
+    /**
+     * Post-process the codegen models to convert OpenAPI types to Python types in anyOf/oneOf.
+     */
+    @Override
+    public ModelsMap postProcessModels(ModelsMap objs) {
+        for (ModelMap mo : objs.getModels()) {
+            CodegenModel model = mo.getModel();
+            if (model.anyOf != null && !model.anyOf.isEmpty()) {
+                Set<String> pythonTypes = new LinkedHashSet<>();
+                for (String type : model.anyOf) {
+                    pythonTypes.add(toPythonType(type));
+                }
+                model.anyOf = pythonTypes;
+            }
+            if (model.oneOf != null && !model.oneOf.isEmpty()) {
+                Set<String> pythonTypes = new LinkedHashSet<>();
+                for (String type : model.oneOf) {
+                    pythonTypes.add(toPythonType(type));
+                }
+                model.oneOf = pythonTypes;
+            }
+        }
+        return postProcessModelsEnum(objs);
+    }
+
     @Override
     public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> objs) {
         final Map<String, ModelsMap> processed = super.postProcessAllModels(objs);
@@ -1389,12 +1446,6 @@ public String addRegularExpressionDelimiter(String pattern) {
         return pattern;
     }
 
-    @Override
-    public ModelsMap postProcessModels(ModelsMap objs) {
-        // process enum in models
-        return postProcessModelsEnum(objs);
-    }
-
     @Override
     public String toEnumVarName(String name, String datatype) {
         if ("int".equals(datatype) || "float".equals(datatype)) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonPydanticV1Codegen.java

@@ -1937,10 +1937,60 @@ public String addRegularExpressionDelimiter(String pattern) {
         return pattern;
     }
 
+    private String toPythonType(String openApiType) {
+        if (openApiType == null) {
+            return "Any";
+        }
+        if (openApiType.startsWith("array[")) {
+            String innerType = openApiType.substring(6, openApiType.length() - 1);
+            return "List[" + toPythonType(innerType) + "]";
+        }
+        if (openApiType.startsWith("map[")) {
+            String innerType = openApiType.substring(4, openApiType.length() - 1);
+            return "Dict[" + innerType + "]";
+        }
+        switch (openApiType) {
+            case "string":
+                return "str";
+            case "array":
+                return "List";
+            case "object":
+                return "Dict";
+            case "number":
+                return "float";
+            case "integer":
+                return "int";
+            case "boolean":
+                return "bool";
+            case "binary":
+                return "bytes";
+            default:
+                return openApiType;
+        }
+    }
+
     @Override
     public ModelsMap postProcessModels(ModelsMap objs) {
         // process enum in models
-        return postProcessModelsEnum(objs);
+        ModelsMap processed = postProcessModelsEnum(objs);
+        for (ModelMap modelMap : processed.getModels()) {
+            CodegenModel model = modelMap.getModel();
+            if (model.anyOf != null && !model.anyOf.isEmpty()) {
+                Set<String> pythonTypes = new LinkedHashSet<>();
+                for (String type : model.anyOf) {
+                    pythonTypes.add(toPythonType(type));
+                }
+                model.anyOf = pythonTypes;
+            }
+            if (model.oneOf != null && !model.oneOf.isEmpty()) {
+                Set<String> pythonTypes = new LinkedHashSet<>();
+                for (String type : model.oneOf) {
+                    pythonTypes.add(toPythonType(type));
+                }
+                model.oneOf = pythonTypes;
+            }
+        }
+        return processed;
     }
 
     @Override

modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonClientCodegenTest.java

@@ -685,4 +685,30 @@ public void testNonPoetry1LicenseFormat() throws IOException {
         // Verify it does NOT use the legacy string format
         TestUtils.assertFileNotContains(pyprojectPath, "license = \"BSD-3-Clause\"");
     }
+
+    @Test(description = "Test anyOf with string and array types - issue #17754")
+    public void testAnyOfStringArrayTypes() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+            .setGeneratorName("python")
+            .setInputSpec("src/test/resources/3_0/issue_17754_anyof_string_array.yaml")
+            .setOutputDir(output.getAbsolutePath());
+
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        // The anyOf creates an inline model - check that model
+        Path valueModelPath = Paths.get(output.getAbsolutePath(), "openapi_client", "models", "key_value_pair_value.py");
+        TestUtils.assertFileExists(valueModelPath);
+
+        String content = Files.readAllLines(valueModelPath).stream().collect(Collectors.joining("\n"));
+
+        // The anyOf schemas should contain Python types (str, List[str]) not OpenAPI types (string, array)
+        // Check that ANY_OF_SCHEMAS contains "List[str]" and "str"
+        Assert.assertTrue(content.contains("KEYVALUEPAIRVALUE_ANY_OF_SCHEMAS = [\"List[str]\", \"str\"]"),
+            "Expected anyOf schemas to contain Python types: List[str], str");
+    }
 }

modules/openapi-generator/src/test/resources/3_0/issue_17754_anyof_string_array.yaml

@@ -0,0 +1,27 @@
+openapi: 3.1.0
+info:
+  title: Test anyOf with string and array
+  version: 1.0.0
+paths:
+  /:
+    get:
+      responses:
+        '200':
+          description: Request successful
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/KeyValuePair'
+components:
+  schemas:
+    KeyValuePair:
+      properties:
+        key:
+          type: string
+        value:
+          anyOf:
+            - items:
+                type: string
+              type: array
+            - type: string
+      type: object