fix: resolve flake8 error

Author: baominghelly

.pre-commit-config.yaml

@@ -9,6 +9,10 @@ repos:
     rev: 6.1.0
     hooks:
     -   id: flake8
-        # Use .flake8 for configuration (separate file to avoid TOML parsing issues)
-        # --exit-zero: show warnings but don't fail pre-commit
-        args: ['--config', '.flake8', '--exit-zero']
+        # Match GitHub CI: check for syntax errors and undefined names
+        # E9: Runtime errors (IndentationError, SyntaxError)
+        # F63: Assertion errors
+        # F7: Various errors
+        # F82: Undefined names
+        args: ['--select=E9,F63,F7,F82', '--show-source', '--statistics']
+

dashboard/utils/data_loader.py

@@ -1,9 +1,14 @@
 #!/usr/bin/env python3
 """Unified data loader for InfiniMetrics dashboard."""
 
+from __future__ import annotations
+
 import logging
 from pathlib import Path
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from .mongo_data_source import MongoDataSource
 
 from .data_sources import DataSource, FileDataSource
 from .data_utils import extract_accelerator_types, extract_run_info, get_friendly_size
@@ -48,7 +53,7 @@ def __init__(
         else:
             self._source = FileDataSource(results_dir)
 
-    def _try_connect_mongo(self) -> Optional["MongoDataSource"]:
+    def _try_connect_mongo(self) -> Optional[MongoDataSource]:
         """
         Try to connect to MongoDB.
 
@@ -65,7 +70,7 @@ def _try_connect_mongo(self) -> Optional["MongoDataSource"]:
             logger.warning(f"MongoDB dependencies not installed ({e})")
         return None
 
-    def _apply_mongo_or_fallback(self, mongo_source: Optional["MongoDataSource"]):
+    def _apply_mongo_or_fallback(self, mongo_source: Optional[MongoDataSource]):
         """Apply MongoDB source or fallback to files based on configuration."""
         if mongo_source:
             self._source = mongo_source