From eed01a2cf3fa795a8d6fe3ca531ba1f60cfd0de4 Mon Sep 17 00:00:00 2001
From: Glenn Jocher <glenn.jocher@ultralytics.com>
Date: Sun, 31 Mar 2024 05:01:30 +0200
Subject: [PATCH] Faster `best.pt` checkpoint saving (#9436)

---
 ultralytics/engine/trainer.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ultralytics/engine/trainer.py b/ultralytics/engine/trainer.py
index 5fa40ad4..8a993c25 100644
--- a/ultralytics/engine/trainer.py
+++ b/ultralytics/engine/trainer.py
@@ -500,9 +500,9 @@ class BaseTrainer:
         # Save last and best
         torch.save(ckpt, self.last)
         if self.best_fitness == self.fitness:
-            torch.save(ckpt, self.best)
+            self.best.write_bytes(self.last.read_bytes())  # copy last.pt to best.pt
         if (self.save_period > 0) and (self.epoch > 0) and (self.epoch % self.save_period == 0):
-            torch.save(ckpt, self.wdir / f"epoch{self.epoch}.pt")
+            (self.wdir / f"epoch{self.epoch}.pt").write_bytes(self.last.read_bytes())  # copy last.pt to i.e. epoch3.pt
 
     @staticmethod
     def get_dataset(data):