Update detect.py (ultralytics#3087)

* Update detect.py

* Update detect.py

detect.py

@@ -5,7 +5,6 @@
 import cv2
 import torch
 import torch.backends.cudnn as cudnn
-from numpy import random
 
 from models.experimental import attempt_load
 from utils.datasets import LoadStreams, LoadImages
@@ -79,7 +78,7 @@ def detect(opt):
         # Process detections
         for i, det in enumerate(pred):  # detections per image
             if webcam:  # batch_size >= 1
-                p, s, im0, frame = path[i], '%g: ' % i, im0s[i].copy(), dataset.count
+                p, s, im0, frame = path[i], f'{i}: ', im0s[i].copy(), dataset.count
             else:
                 p, s, im0, frame = path, '', im0s.copy(), getattr(dataset, 'frame', 0)
 
@@ -108,7 +107,6 @@ def detect(opt):
                     if save_img or opt.save_crop or view_img:  # Add bbox to image
                         c = int(cls)  # integer class
                         label = None if opt.hide_labels else (names[c] if opt.hide_conf else f'{names[c]} {conf:.2f}')
-
                         plot_one_box(xyxy, im0, label=label, color=colors(c, True), line_thickness=opt.line_thickness)
                         if opt.save_crop:
                             save_one_box(xyxy, im0s, file=save_dir / 'crops' / names[c] / f'{p.stem}.jpg', BGR=True)