Ultralytics Code Refactor https://ultralytics.com/actions (#13152)

Refactor code for speed and clarity

segment/train.py

@@ -216,6 +216,7 @@ def train(hyp, opt, device, callbacks):
     else:
 
         def lf(x):
+            """Linear learning rate scheduler decreasing from 1 to hyp['lrf'] over 'epochs'."""
             return (1 - x / epochs) * (1.0 - hyp["lrf"]) + hyp["lrf"]  # linear
 
     scheduler = lr_scheduler.LambdaLR(optimizer, lr_lambda=lf)  # plot_lr_scheduler(optimizer, scheduler, epochs)