[Python] Correct sanitize_for_serialization in python generator for list in oneOf schema elements, fixes #18106 (#19405)

* correct sanitize_for_serialization in python generator, fixes #18106

The method did not consider the objects created for oneOf schemata. If one of the cases was a list, to_dict would return it instead of something that has an items() method.

* generate new samples

Author: karge-itestra

modules/openapi-generator/src/main/resources/python/api_client.mustache

@@ -390,6 +390,10 @@ class ApiClient:
             else:
                 obj_dict = obj.__dict__
 
+        if isinstance(obj_dict, list):
+            # here we handle instances that can either be a list or something else, and only became a real list by calling to_dict()
+            return self.sanitize_for_serialization(obj_dict)
+
         return {
             key: self.sanitize_for_serialization(val)
             for key, val in obj_dict.items()

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/openapi_client/api_client.py

@@ -383,6 +383,10 @@ def sanitize_for_serialization(self, obj):
             else:
                 obj_dict = obj.__dict__
 
+        if isinstance(obj_dict, list):
+            # here we handle instances that can either be a list or something else, and only became a real list by calling to_dict()
+            return self.sanitize_for_serialization(obj_dict)
+
         return {
             key: self.sanitize_for_serialization(val)
             for key, val in obj_dict.items()

samples/client/echo_api/python/openapi_client/api_client.py

@@ -383,6 +383,10 @@ def sanitize_for_serialization(self, obj):
             else:
                 obj_dict = obj.__dict__
 
+        if isinstance(obj_dict, list):
+            # here we handle instances that can either be a list or something else, and only became a real list by calling to_dict()
+            return self.sanitize_for_serialization(obj_dict)
+
         return {
             key: self.sanitize_for_serialization(val)
             for key, val in obj_dict.items()

samples/openapi3/client/petstore/python-aiohttp/petstore_api/api_client.py

@@ -385,6 +385,10 @@ def sanitize_for_serialization(self, obj):
             else:
                 obj_dict = obj.__dict__
 
+        if isinstance(obj_dict, list):
+            # here we handle instances that can either be a list or something else, and only became a real list by calling to_dict()
+            return self.sanitize_for_serialization(obj_dict)
+
         return {
             key: self.sanitize_for_serialization(val)
             for key, val in obj_dict.items()

samples/openapi3/client/petstore/python/petstore_api/api_client.py

@@ -382,6 +382,10 @@ def sanitize_for_serialization(self, obj):
             else:
                 obj_dict = obj.__dict__
 
+        if isinstance(obj_dict, list):
+            # here we handle instances that can either be a list or something else, and only became a real list by calling to_dict()
+            return self.sanitize_for_serialization(obj_dict)
+
         return {
             key: self.sanitize_for_serialization(val)
             for key, val in obj_dict.items()