diff --git a/apps/api/app/services/smart_asset_selector.py b/apps/api/app/services/smart_asset_selector.py
index 8e781f508..7878b1bd5 100755
--- a/apps/api/app/services/smart_asset_selector.py
+++ b/apps/api/app/services/smart_asset_selector.py
@@ -18,7 +18,6 @@
 from __future__ import annotations
 
 import logging
-import math
 from dataclasses import dataclass
 
 logger = logging.getLogger(__name__)
@@ -278,9 +277,7 @@ class SmartAssetSelector:
         # 分桶
         short_bucket = [d for d in scored if d.duration is not None and d.duration < _SHORT_BUCKET_MAX]
         medium_bucket = [
-            d
-            for d in scored
-            if d.duration is not None and _SHORT_BUCKET_MAX <= d.duration < _MEDIUM_BUCKET_MAX
+            d for d in scored if d.duration is not None and _SHORT_BUCKET_MAX <= d.duration < _MEDIUM_BUCKET_MAX
         ]
         long_bucket = [d for d in scored if d.duration is not None and d.duration >= _MEDIUM_BUCKET_MAX]
         unknown_bucket = [d for d in scored if d.duration is None]
@@ -295,7 +292,7 @@ class SmartAssetSelector:
         selected_ids: set[str] = set()
 
         # 先按配额从每个桶取
-        for bucket, name in zip(buckets, bucket_names):
+        for bucket, _name in zip(buckets, bucket_names, strict=False):
             quota = min(base_quota, len(bucket))
             if quota <= 0:
                 continue
diff --git a/tests/unit/test_ai_service.py b/tests/unit/test_ai_service.py
index f83e408ae..4049f9687 100755
--- a/tests/unit/test_ai_service.py
+++ b/tests/unit/test_ai_service.py
@@ -20,8 +20,8 @@ sys.path.insert(0, "apps/api")
 from app.services.ai_service import (  # noqa: E402
     TITLE_STYLES,
     _generate_titles_fallback,
-    _parse_titles_from_response,
     _parse_semantic_match_response,
+    _parse_titles_from_response,
     _semantic_match_fallback,
     generate_smart_titles,
     semantic_match_assets,
@@ -76,7 +76,7 @@ class TestTitleParsing(unittest.TestCase):
 
     def test_parse_markdown_code_block_json(self):
         """解析 markdown 代码块包裹的 JSON."""
-        content = "```json\n[\"标题1\", \"标题2\"]\n```"
+        content = '```json\n["标题1", "标题2"]\n```'
         result = _parse_titles_from_response(content)
         self.assertEqual(len(result), 2)
 
@@ -209,9 +209,7 @@ class TestGenerateSmartTitles(unittest.TestCase):
         mock_client = MagicMock()
         mock_client.is_available = True
         # 返回无法解析的内容（只有一个标题且格式异常）
-        mock_client.chat_completion = MagicMock(
-            return_value="一段文字说明，不是标题列表"
-        )
+        mock_client.chat_completion = MagicMock(return_value="一段文字说明，不是标题列表")
         with patch("app.services.ai_service.get_doubao_client", return_value=mock_client):
             result = generate_smart_titles("测试视频", "viral", 5)
             # 只有1个有效标题，不足2个触发降级
@@ -223,7 +221,7 @@ class TestTitleStyles(unittest.TestCase):
 
     def test_all_styles_have_required_fields(self):
         """所有风格都有必要字段."""
-        for key, info in TITLE_STYLES.items():
+        for _key, info in TITLE_STYLES.items():
             self.assertIn("name", info)
             self.assertIn("description", info)
             self.assertIn("examples", info)
@@ -310,12 +308,14 @@ class TestSemanticMatchParsing(unittest.TestCase):
 
     def test_parse_matches_list_format(self):
         """解析 {matches: [...]} 格式."""
-        content = json.dumps({
-            "matches": [
-                {"asset_id": "a1", "score": 0.9},
-                {"asset_id": "a2", "score": 0.7},
-            ]
-        })
+        content = json.dumps(
+            {
+                "matches": [
+                    {"asset_id": "a1", "score": 0.9},
+                    {"asset_id": "a2", "score": 0.7},
+                ]
+            }
+        )
         result = _parse_semantic_match_response(content, ["a1", "a2"])
         self.assertIsNotNone(result)
         self.assertAlmostEqual(result["a1"], 0.9)
@@ -323,10 +323,12 @@ class TestSemanticMatchParsing(unittest.TestCase):
 
     def test_parse_array_format(self):
         """解析数组格式."""
-        content = json.dumps([
-            {"id": "x1", "score": 0.5},
-            {"id": "x2", "score": 0.88},
-        ])
+        content = json.dumps(
+            [
+                {"id": "x1", "score": 0.5},
+                {"id": "x2", "score": 0.88},
+            ]
+        )
         result = _parse_semantic_match_response(content, ["x1", "x2"])
         self.assertIsNotNone(result)
         self.assertAlmostEqual(result["x1"], 0.5)
@@ -341,7 +343,7 @@ class TestSemanticMatchParsing(unittest.TestCase):
 
     def test_parse_markdown_code_block(self):
         """解析markdown代码块."""
-        content = "```json\n{\"a1\": 0.7}\n```"
+        content = '```json\n{"a1": 0.7}\n```'
         result = _parse_semantic_match_response(content, ["a1", "a2"])
         # 只有1个素材评分，少于一半（需要至少1个，max(1, 2//2)=1）
         self.assertIsNotNone(result)
@@ -396,9 +398,7 @@ class TestSemanticMatchAssets(unittest.TestCase):
         """豆包调用成功路径."""
         mock_client = MagicMock()
         mock_client.is_available = True
-        mock_client.chat_completion = MagicMock(
-            return_value=json.dumps({"a1": 0.9, "a2": 0.5, "a3": 0.2})
-        )
+        mock_client.chat_completion = MagicMock(return_value=json.dumps({"a1": 0.9, "a2": 0.5, "a3": 0.2}))
         with patch("app.services.ai_service.get_doubao_client", return_value=mock_client):
             result = semantic_match_assets("风景视频", self._make_assets())
             self.assertEqual(result["source"], "doubao")