fix(python-fastapi): remove 200 fallback code and use default (#12481) (#21333)

Co-authored-by: Thomas Sickinger <[email protected]>

Author: sickinga

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

@@ -232,15 +232,6 @@ public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<Mo
         if (operations != null) {
             List<CodegenOperation> ops = operations.getOperation();
             for (final CodegenOperation operation : ops) {
-                List<CodegenResponse> responses = operation.responses;
-                if (responses != null) {
-                    for (final CodegenResponse resp : responses) {
-                        // Convert "default" value (0) to OK (200).
-                        if ("0".equals(resp.code)) {
-                            resp.code = "200";
-                        }
-                    }
-                }
                 List<CodegenSecurity> securityMethods = operation.authMethods;
                 if (securityMethods != null) {
                     for (final CodegenSecurity securityMethod : securityMethods) {

modules/openapi-generator/src/main/resources/python-fastapi/api.mustache

@@ -41,7 +41,7 @@ for _, name, _ in pkgutil.iter_modules(ns_pkg.__path__, ns_pkg.__name__ + "."):
     "{{{path}}}",
     responses={
         {{#responses}}
-        {{code}}: {{=<% %>=}}{<%#dataType%>"model": <%dataType%>, "description": "<%message%>"<%/dataType%><%^dataType%>"description": "<%message%>"<%/dataType%>}<%={{ }}=%>,
+        {{#isDefault}}"default"{{/isDefault}}{{^isDefault}}{{code}}{{/isDefault}}: {{=<% %>=}}{<%#dataType%>"model": <%dataType%>, "description": "<%message%>"<%/dataType%><%^dataType%>"description": "<%message%>"<%/dataType%>}<%={{ }}=%>,
         {{/responses}}
     },
     tags=[{{#tags}}"{{name}}"{{^-last}},{{/-last}}{{/tags}}],

samples/server/petstore/python-fastapi/src/openapi_server/apis/user_api.py

@@ -39,7 +39,7 @@
 @router.post(
     "/user",
     responses={
-        200: {"description": "successful operation"},
+        "default": {"description": "successful operation"},
     },
     tags=["user"],
     summary="Create user",
@@ -60,7 +60,7 @@ async def create_user(
 @router.post(
     "/user/createWithArray",
     responses={
-        200: {"description": "successful operation"},
+        "default": {"description": "successful operation"},
     },
     tags=["user"],
     summary="Creates list of users with given input array",
@@ -81,7 +81,7 @@ async def create_users_with_array_input(
 @router.post(
     "/user/createWithList",
     responses={
-        200: {"description": "successful operation"},
+        "default": {"description": "successful operation"},
     },
     tags=["user"],
     summary="Creates list of users with given input array",
@@ -164,7 +164,7 @@ async def login_user(
 @router.get(
     "/user/logout",
     responses={
-        200: {"description": "successful operation"},
+        "default": {"description": "successful operation"},
     },
     tags=["user"],
     summary="Logs out current logged in user session",