add missing and modern typehints (#302)

* add missing and modern typehints
* Remove unused import from __init__.py
* add missing `: object` to __exit__ *_ params for consistency
* add TYPE_CHECKING and annotations to resolve potential circular imports

---------

Co-authored-by: Piotr Skalski <piotr.skalski92@gmail.com>
Co-authored-by: jirka <6035284+Borda@users.noreply.github.com>
Co-authored-by: Claude Code <noreply@anthropic.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 5 people

test/core/test_tracker_integration.py

@@ -70,6 +70,7 @@ def _run_tracker_on_flat_dataset(
                 tracked = tracker.update(detections)
                 if tracked.tracker_id is not None:
                     mature = tracked[tracked.tracker_id != -1]
+                    assert isinstance(mature, sv.Detections)
                     mot.write(frame_idx, mature)
                 else:
                     mot.write(frame_idx, tracked)
@@ -110,6 +111,9 @@ def test_tracker_regression(
     )
 
     aggregate = result.aggregate
+    assert aggregate.HOTA is not None
+    assert aggregate.CLEAR is not None
+    assert aggregate.Identity is not None
     assert aggregate.HOTA.HOTA * 100 == pytest.approx(expected["HOTA"], abs=0.001)
     assert aggregate.CLEAR.MOTA * 100 == pytest.approx(expected["MOTA"], abs=0.001)
     assert aggregate.Identity.IDF1 * 100 == pytest.approx(expected["IDF1"], abs=0.001)

trackers/core/bytetrack/kalman.py

@@ -51,7 +51,7 @@ def get_next_tracker_id(cls) -> int:
         cls.count_id += 1
         return next_id
 
-    def __init__(self, bbox: np.ndarray):
+    def __init__(self, bbox: np.ndarray) -> None:
         # Initialize with a temporary ID of -1
         # Will be assigned a real ID when the track is considered mature
         self.tracker_id = -1

trackers/eval/__init__.py

@@ -6,6 +6,10 @@
 
 """Evaluation metrics and utilities for tracking benchmarks."""
 
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
 from trackers.eval.box import box_ioa, box_iou
 from trackers.eval.clear import aggregate_clear_metrics, compute_clear_metrics
 from trackers.eval.hota import aggregate_hota_metrics, compute_hota_metrics
@@ -18,8 +22,11 @@
     SequenceResult,
 )
 
+if TYPE_CHECKING:
+    from trackers.eval.evaluate import evaluate_mot_sequence, evaluate_mot_sequences
+
 
-def __getattr__(name: str):
+def __getattr__(name: str) -> object:
     """Lazy imports for evaluate functions to avoid circular imports."""
     if name in ("evaluate_mot_sequence", "evaluate_mot_sequences"):
         from trackers.eval import evaluate as _evaluate

trackers/io/mot.py

@@ -9,6 +9,7 @@
 import csv
 from dataclasses import dataclass
 from pathlib import Path
+from typing import TextIO
 
 import numpy as np
 import supervision as sv
@@ -418,9 +419,9 @@ def _prepare_mot_sequence(
 class _MOTOutput:
     """Context manager for MOT format file writing."""
 
-    def __init__(self, path: Path | None):
+    def __init__(self, path: Path | None) -> None:
         self.path = path
-        self._file = None
+        self._file: TextIO | None = None
 
     def write(self, frame_idx: int, detections: sv.Detections) -> None:
         """Write detections for a frame in MOT format."""
@@ -447,12 +448,12 @@ def write(self, frame_idx: int, detections: sv.Detections) -> None:
                 f"{conf:.4f},-1,-1,-1\n"
             )
 
-    def __enter__(self):
+    def __enter__(self) -> _MOTOutput:
         if self.path is not None:
             self.path.parent.mkdir(parents=True, exist_ok=True)
             self._file = open(self.path, "w")
         return self
 
-    def __exit__(self, *_):
+    def __exit__(self, *_: object) -> None:
         if self._file is not None:
             self._file.close()

trackers/io/video.py

@@ -90,7 +90,7 @@ def _iter_image_folder_frames(
 class _VideoOutput:
     """Context manager for lazy video file writing."""
 
-    def __init__(self, path: Path | None, *, fps: float = _DEFAULT_OUTPUT_FPS):
+    def __init__(self, path: Path | None, *, fps: float = _DEFAULT_OUTPUT_FPS) -> None:
         self.path = path
         self.fps = fps
         self._writer: cv2.VideoWriter | None = None
@@ -137,7 +137,7 @@ def __exit__(self, *_: object) -> None:
 class _DisplayWindow:
     """Context manager for OpenCV display window with resizable output."""
 
-    def __init__(self, window_name: str = "Tracking"):
+    def __init__(self, window_name: str = "Tracking") -> None:
         self.window_name = window_name
         self._quit_requested = False
         cv2.namedWindow(self.window_name, cv2.WINDOW_NORMAL | cv2.WINDOW_KEEPRATIO)
@@ -159,8 +159,8 @@ def quit_requested(self) -> bool:
         """Return True if user pressed quit key."""
         return self._quit_requested
 
-    def __enter__(self):
+    def __enter__(self) -> _DisplayWindow:
         return self
 
-    def __exit__(self, *_):
+    def __exit__(self, *_: object) -> None:
         cv2.destroyWindow(self.window_name)

trackers/scripts/track.py

@@ -11,6 +11,7 @@
 import sys
 from contextlib import nullcontext
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import numpy as np
 import supervision as sv
@@ -23,6 +24,9 @@
 from trackers.scripts.progress import _classify_source, _SourceInfo, _TrackingProgress
 from trackers.utils.device import _best_device
 
+if TYPE_CHECKING:
+    from inference_models import AnyModel
+
 # Defaults
 DEFAULT_MODEL = "rfdetr-nano"
 DEFAULT_TRACKER = "bytetrack"
@@ -555,7 +559,7 @@ def _init_model(
     *,
     device: str = DEFAULT_DEVICE,
     api_key: str | None = None,
-):
+) -> AnyModel:
     """Load detection model via inference-models.
 
     Args:
@@ -585,7 +589,7 @@ def _init_model(
     )
 
 
-def _run_model(model, frame: np.ndarray, confidence: float) -> sv.Detections:
+def _run_model(model: AnyModel, frame: np.ndarray, confidence: float) -> sv.Detections:
     """Run model inference and return sv.Detections."""
     predictions = model(frame)
     if not predictions:
@@ -627,7 +631,7 @@ def _extract_tracker_params(
     return params
 
 
-def _init_tracker(tracker_id: str, **kwargs) -> BaseTracker:
+def _init_tracker(tracker_id: str, **kwargs: object) -> BaseTracker:
     """Create tracker instance from registry.
 
     Args: