[Python] Add Flag to Allow Ignoring Operation Servers (#18981)

* [Python] Add Flag to Allow Ignoring Operation Servers

* generate samples

* add tests

samples/openapi3/client/petstore/python-aiohttp/tests/test_api_client.py

@@ -8,6 +8,7 @@ import weakref
 from tests.util import async_test
 import petstore_api
 
+HOST = 'http://localhost/v2'
 
 class TestApiClient(unittest.TestCase):
 
@@ -20,3 +21,31 @@ class TestApiClient(unittest.TestCase):
             rest_pool_ref = client.rest_client.pool_manager
 
         self.assertTrue(rest_pool_ref.closed)
+
+    @async_test
+    async def test_ignore_operation_servers(self):
+        config = petstore_api.Configuration(host=HOST)
+        client = petstore_api.ApiClient(config)
+        user_api_instance = petstore_api.api.user_api.UserApi(client)
+
+        config_ignore = petstore_api.Configuration(host=HOST, ignore_operation_servers=True)
+        client_ignore = petstore_api.ApiClient(config_ignore)
+        user_api_instance_ignore = petstore_api.api.user_api.UserApi(client_ignore)
+
+        params_to_serialize = {
+            'user': petstore_api.User(id=1, username='test'),
+            '_request_auth': None,
+            '_content_type': 'application/json',
+            '_headers': None,
+            '_host_index': 0
+        }
+
+        # operation servers should be used
+        _, url, *_ = user_api_instance._create_user_serialize(**params_to_serialize)
+        self.assertEqual(client.configuration.host, HOST)
+        self.assertEqual(url, 'http://petstore.swagger.io/v2/user')
+
+        # operation servers should be ignored
+        _, url_ignore, *_ = user_api_instance_ignore._create_user_serialize(**params_to_serialize)
+        self.assertEqual(client.configuration.host, HOST)
+        self.assertEqual(url_ignore, HOST + '/user')