Fix list type annotations when model property is named "list"

.chronus/changes/copilot-fix-list-property-name-2025-12-22-05-33-41.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/http-client-python"
+---
+
+Fix syntax error when model property is named "list" by using type alias to avoid naming conflicts

packages/http-client-python/generator/pygen/codegen/models/code_model.py

@@ -491,6 +491,10 @@ def _get_relative_generation_dir(self, root_dir: Path, namespace: str) -> Path:
     def has_operation_named_list(self) -> bool:
         return any(o.name.lower() == "list" for c in self.clients for og in c.operation_groups for o in og.operations)
 
+    @property
+    def has_property_named_list(self) -> bool:
+        return any(p.client_name.lower() == "list" for m in self.model_types for p in m.properties)
+
     @property
     def has_padded_model_property(self) -> bool:
         for model_type in self.model_types:

packages/http-client-python/generator/pygen/codegen/models/list_type.py

@@ -41,8 +41,13 @@ def type_annotation(self, **kwargs: Any) -> str:
             # this means we're version tolerant XML, we just return the XML element
             return self.element_type.type_annotation(**kwargs)
 
-        # if there is a function named `list` we have to make sure there's no conflict with the built-in `list`
-        list_type = "List" if self.code_model.has_operation_named_list and kwargs.get("is_operation_file") else "list"
+        # if there is a function/property named `list` we have to make sure there's no conflict with the built-in `list`
+        is_operation_file = kwargs.get("is_operation_file", False)
+        use_list_import = (
+            (self.code_model.has_operation_named_list and is_operation_file) or
+            (self.code_model.has_property_named_list and not is_operation_file)
+        )
+        list_type = "List" if use_list_import else "list"
         return f"{list_type}[{self.element_type.type_annotation(**kwargs)}]"
 
     def description(self, *, is_operation_file: bool) -> str:

packages/http-client-python/generator/pygen/codegen/serializers/model_serializer.py

@@ -285,6 +285,9 @@ def imports(self) -> FileImport:
                 file_import.add_submodule_import("typing", "overload", ImportType.STDLIB)
                 file_import.add_submodule_import("typing", "Mapping", ImportType.STDLIB)
                 file_import.add_submodule_import("typing", "Any", ImportType.STDLIB)
+        # if there is a property named `list` we have to make sure there's no conflict with the built-in `list`
+        if self.code_model.has_property_named_list:
+            file_import.define_mypy_type("List", "list")
         return file_import
 
     def declare_model(self, model: ModelType) -> str: