[python] clean up namespace logic

.chronus/changes/python-cleanUpNamespaceLogic-2026-2-2-17-15-49.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+clean up namespace logic in python

packages/http-client-python/emitter/src/code-model.ts

@@ -263,7 +263,7 @@ function emitOperationGroups<TServiceOperation extends SdkServiceOperation>(
   // operation has same clientNamespace as the operation group
   for (const og of operationGroups) {
     for (const op of og.operations) {
-      op.clientNamespace = getClientNamespace(context, og.clientNamespace);
+      op.clientNamespace = og.clientNamespace;
     }
   }
 

packages/http-client-python/emitter/src/utils.ts

@@ -262,6 +262,7 @@ export function capitalize(name: string): string {
   return name[0].toUpperCase() + name.slice(1);
 }
 
+// Library namespaces that should not be used as client namespaces
 const LIB_NAMESPACE = [
   "azure.core",
   "azure.resourcemanager",
@@ -272,29 +273,25 @@ const LIB_NAMESPACE = [
 ];
 
 export function getRootNamespace(context: PythonSdkContext): string {
-  let rootNamespace = "";
   if (context.sdkPackage.clients.length > 0) {
-    rootNamespace = context.sdkPackage.clients[0].namespace;
-  } else if (context.sdkPackage.models.length > 0) {
-    const result = context.sdkPackage.models
-      .map((model) => model.namespace)
-      .filter((namespace) => !LIB_NAMESPACE.includes(namespace));
-    if (result.length > 0) {
-      result.sort();
-      rootNamespace = result[0];
-    }
+    return context.sdkPackage.clients[0].namespace.toLowerCase();
   } else if (context.sdkPackage.namespaces.length > 0) {
-    rootNamespace = context.sdkPackage.namespaces[0].fullName;
+    return context.sdkPackage.namespaces[0].fullName.toLowerCase();
   }
+  return "";
+}
 
-  return rootNamespace.toLowerCase();
+function isLibraryNamespace(namespace: string): boolean {
+  const ns = namespace.toLowerCase();
+  return LIB_NAMESPACE.some((lib) => ns.startsWith(lib));
 }
 
 export function getClientNamespace(context: PythonSdkContext, clientNamespace: string) {
-  if (
-    clientNamespace === "" ||
-    LIB_NAMESPACE.some((item) => clientNamespace.toLowerCase().startsWith(item))
-  ) {
+  // Namespace precedence: @clientNamespace > --namespace > original namespace
+  // These are resolved by TCGC and passed in as clientNamespace.
+  // However, models from library namespaces (azure.core, azure.resourcemanager, etc.)
+  // should use the SDK's root namespace instead.
+  if (clientNamespace === "" || isLibraryNamespace(clientNamespace)) {
     return getRootNamespace(context);
   }
   return clientNamespace.toLowerCase();