diff --git a/apps/api/app/services/asset_segment_tracker.py b/apps/api/app/services/asset_segment_tracker.py
index cb485816b..6bff40234 100644
--- a/apps/api/app/services/asset_segment_tracker.py
+++ b/apps/api/app/services/asset_segment_tracker.py
@@ -120,8 +120,7 @@ def remove_used_segment(
     for r in ranges:
         try:
             match = (
-                abs(float(r["start"]) - float(start)) <= tolerance
-                and abs(float(r["end"]) - float(end)) <= tolerance
+                abs(float(r["start"]) - float(start)) <= tolerance and abs(float(r["end"]) - float(end)) <= tolerance
             )
         except (KeyError, TypeError, ValueError):
             remaining.append(r)
diff --git a/tests/unit/test_asset_segment_tracker.py b/tests/unit/test_asset_segment_tracker.py
index 043e51b1f..258771c2f 100644
--- a/tests/unit/test_asset_segment_tracker.py
+++ b/tests/unit/test_asset_segment_tracker.py
@@ -22,7 +22,6 @@ os.environ.setdefault("DATABASE_URL", "sqlite:///test.db")
 sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "apps" / "api"))
 
 import pytest
-
 from app.services import asset_segment_tracker as ast
 from app.services.asset_segment_tracker import (
     get_used_segments,
@@ -31,6 +30,7 @@ from app.services.asset_segment_tracker import (
     remove_used_segment,
     reset_used_segments,
 )
+
 from packages.domain.plan_generator_utils import _calc_random_start_time
 
 
@@ -121,12 +121,17 @@ def _db(models):
 
 def test_get_used_segments_aggregates_ranges(patched_model):
     models = {
-        "a1": FakeModel("a1", {"used_time_ranges": [
-            {"start": 1.0, "end": 5.0, "plan_id": "p1"},
-            {"start": 9.0, "end": 12.0, "plan_id": "p2"},
-        ]}),
-        "a2": FakeModel("a2", {"other": 1}),            # 无区间记录
-        "a3": FakeModel("a3"),                           # metadata 为空
+        "a1": FakeModel(
+            "a1",
+            {
+                "used_time_ranges": [
+                    {"start": 1.0, "end": 5.0, "plan_id": "p1"},
+                    {"start": 9.0, "end": 12.0, "plan_id": "p2"},
+                ]
+            },
+        ),
+        "a2": FakeModel("a2", {"other": 1}),  # 无区间记录
+        "a3": FakeModel("a3"),  # metadata 为空
     }
     db = _db(models)
 
@@ -202,12 +207,8 @@ def test_remove_not_found_returns_false(patched_model):
 
 def test_remove_respects_tolerance(patched_model):
     models = {
-        "a1": FakeModel("a1", {"used_time_ranges": [
-            {"start": 5.0, "end": 9.0, "plan_id": "p1"}
-        ]}),
-        "a2": FakeModel("a2", {"used_time_ranges": [
-            {"start": 5.0, "end": 9.0, "plan_id": "p1"}
-        ]}),
+        "a1": FakeModel("a1", {"used_time_ranges": [{"start": 5.0, "end": 9.0, "plan_id": "p1"}]}),
+        "a2": FakeModel("a2", {"used_time_ranges": [{"start": 5.0, "end": 9.0, "plan_id": "p1"}]}),
     }
     db = _db(models)
 
@@ -218,9 +219,7 @@ def test_remove_respects_tolerance(patched_model):
 
 
 def test_remove_plan_id_must_match(patched_model):
-    models = {"a1": FakeModel("a1", {"used_time_ranges": [
-        {"start": 5.0, "end": 9.0, "plan_id": "plan-A"}
-    ]})}
+    models = {"a1": FakeModel("a1", {"used_time_ranges": [{"start": 5.0, "end": 9.0, "plan_id": "plan-A"}]})}
     db = _db(models)
 
     # 时间匹配但 plan_id 不同 → 不删除
@@ -232,10 +231,15 @@ def test_remove_plan_id_must_match(patched_model):
 
 
 def test_reset_clears_ranges_keeps_other_fields(patched_model):
-    models = {"a1": FakeModel("a1", {
-        "generation_use_count": 9,
-        "used_time_ranges": [{"start": 1, "end": 2}],
-    })}
+    models = {
+        "a1": FakeModel(
+            "a1",
+            {
+                "generation_use_count": 9,
+                "used_time_ranges": [{"start": 1, "end": 2}],
+            },
+        )
+    }
     db = _db(models)
 
     reset_used_segments(db, "a1")
@@ -250,17 +254,15 @@ def test_reset_clears_ranges_keeps_other_fields(patched_model):
 
 
 def test_reset_callback_clears_persisted_and_memory(patched_model):
-    models = {"a1": FakeModel("a1", {"used_time_ranges": [
-        {"start": 0, "end": 30}
-    ]})}
+    models = {"a1": FakeModel("a1", {"used_time_ranges": [{"start": 0, "end": 30}]})}
     db = _db(models)
 
     used_segments = {"a1": [(0.0, 30.0)], "a2": [(1.0, 2.0)]}
     cb = make_reset_callback(db, used_segments)
     cb("a1")
 
-    assert "a1" not in used_segments     # 内存清空
-    assert "a2" in used_segments         # 其他素材不受影响
+    assert "a1" not in used_segments  # 内存清空
+    assert "a2" in used_segments  # 其他素材不受影响
     assert models["a1"].meta()["used_time_ranges"] == []
 
 
@@ -277,9 +279,7 @@ def test_calc_random_start_invokes_reset_when_exhausted():
         reset_called.append(asset_id)
         used.pop(asset_id, None)  # 模拟轮回清空
 
-    result = _calc_random_start_time(
-        "a1", 10.0, durations, used, on_exhausted=_on_exhausted
-    )
+    result = _calc_random_start_time("a1", 10.0, durations, used, on_exhausted=_on_exhausted)
 
     assert reset_called == ["a1"]
     assert result is not None
@@ -302,9 +302,7 @@ def test_calc_random_start_with_space_does_not_reset():
     used = {"a1": [(0.0, 50.0)]}
     reset_called = []
 
-    result = _calc_random_start_time(
-        "a1", 5.0, durations, used, on_exhausted=lambda aid: reset_called.append(aid)
-    )
+    result = _calc_random_start_time("a1", 5.0, durations, used, on_exhausted=lambda aid: reset_called.append(aid))
 
     assert reset_called == []
     assert result is not None