chore(ruff): enable dictionary iteration checks

marimo/_runtime/commands.py

@@ -182,10 +182,11 @@ def _url_to_dict(url: URL) -> dict[str, Encodable]:
             query_params[k].append(str(v))
 
         # Convert headers to dict, remove all marimo-specific headers
-        headers: dict[str, str] = {}
-        for k, v in request.headers.items():
-            if not k.startswith(("marimo", "x-marimo")):
-                headers[k] = v
+        headers: dict[str, str] = {
+            k: v
+            for k, v in request.headers.items()
+            if not k.startswith(("marimo", "x-marimo"))
+        }
 
         return HTTPRequest(
             url=url_dict,

marimo/_runtime/reload/module_watcher.py

@@ -125,7 +125,6 @@ def _check_modules(
     sys_modules: dict[str, types.ModuleType],
 ) -> dict[str, types.ModuleType]:
     """Returns the set of modules used by the graph that have been modified"""
-    stale_modules: dict[str, types.ModuleType] = {}
     modified_modules = reloader.check(modules=sys_modules, reload=False)
     # TODO(akshayka): could also exclude modules part of the standard library;
     # haven't found a reliable way to do this, however.
@@ -136,15 +135,17 @@ def _check_modules(
         t.__file__ for t in target_modules if hasattr(t, "__file__")
     }
 
-    for modname, module in modules.items():
+    stale_modules: dict[str, types.ModuleType] = {
+        modname: module
+        for modname, module in modules.items()
         if _depends_on(
             src_module=module,
             target_modules=target_modules,
             target_filenames=target_filenames,
             excludes=excludes,
             reloader=reloader,
-        ):
-            stale_modules[modname] = module
+        )
+    }
     return stale_modules
 
 

marimo/_runtime/utils/set_ui_element_request_manager.py

@@ -83,8 +83,7 @@ def _merge_ui_commands(
     merged: dict[UIElementId, Any] = {}
     last_cmd = cmds[-1]
     for cmd in cmds:
-        for ui_id, value in cmd.ids_and_values:
-            merged[ui_id] = value
+        merged.update(cmd.ids_and_values)
 
     return [
         UpdateUIElementCommand(

marimo/_session/state/session_view.py

@@ -305,10 +305,11 @@ def add_notification(self, notification: NotificationMessage) -> None:
             }
 
             # Remove any variable values that are no longer in scope.
-            next_values: dict[str, VariableValue] = {}
-            for name, value in self.variable_values.items():
-                if name in variable_names:
-                    next_values[name] = value
+            next_values: dict[str, VariableValue] = {
+                name: value
+                for name, value in self.variable_values.items()
+                if name in variable_names
+            }
             self.variable_values = next_values
 
             # Remove any table values that are no longer in scope.

pyproject.toml

@@ -350,7 +350,6 @@ ignore = [
     "TC006", # Add quotes to type expression in typing.cast()
     "PERF203", # try-except within a loop incurs performance overhead; not always possible
     "PERF401", # Use {message_str} to create a transformed list; at the cost of readability
-    "PERF403", # Use a dictionary comprehension instead of a for-loop; at the cost of readability
     # TODO: we should fix these, and enable this rule
     "PT011", # `pytest.raises(ValueError)` is too broad, set the `match` parameter or use a more specific exception
     "E501",  # Line too long, we still trim