fix linting and add comments

deepface/detectors/YunetWrapper.py

@@ -13,9 +13,7 @@ def build_model():
  print(f"{file_name} will be downloaded...")
  output = home + f"/.deepface/weights/{file_name}"
  gdown.download(url, output, quiet=False)
- face_detector = cv2.FaceDetectorYN_create(
- home + f"/.deepface/weights/{file_name}", "", (0, 0)
- )
+ face_detector = cv2.FaceDetectorYN_create(home + f"/.deepface/weights/{file_name}", "", (0, 0))
  return face_detector
 
 
@@ -52,10 +50,11 @@ def detect_face(detector, image, align=True, score_threshold=0.9):
  {x, y}_{re, le, nt, rcm, lcm} stands for the coordinates of right eye, left eye, nose tip, the right corner and left corner of the mouth respectively.
  """
  (x, y, w, h, x_re, y_re, x_le, y_le) = list(map(int, face[:8]))
- if x < 0:
- x = 0
- if y < 0:
- y = 0
+
+ # Yunet returns negative coordinates if it thinks part of the detected face is outside the frame.
+ # We set the coordinate to 0 if they are negative.
+ x = max(x, 0)
+ y = max(y, 0)
  if resized:
  image = original_image
  x, y, w, h = int(x / r), int(y / r), int(w / r), int(h / r)