fix negative collector time (#578)

setup.py

@@ -30,6 +30,7 @@ def get_extras_require() -> str:
         "dev": [
             "sphinx<4",
             "sphinx_rtd_theme",
+            "jinja2<3.1",  # temporary fix
             "sphinxcontrib-bibtex",
             "flake8",
             "flake8-bugbear",

tianshou/trainer/utils.py

@@ -35,8 +35,8 @@ def test_episode(
 
 def gather_info(
     start_time: float,
-    train_c: Optional[Collector],
-    test_c: Optional[Collector],
+    train_collector: Optional[Collector],
+    test_collector: Optional[Collector],
     best_reward: float,
     best_reward_std: float,
 ) -> Dict[str, Union[float, str]]:
@@ -57,38 +57,40 @@ def gather_info(
         * ``best_reward`` the best reward over the test results;
         * ``duration`` the total elapsed time.
     """
-    duration = time.time() - start_time
+    duration = max(0, time.time() - start_time)
     model_time = duration
     result: Dict[str, Union[float, str]] = {
         "duration": f"{duration:.2f}s",
         "train_time/model": f"{model_time:.2f}s",
     }
-    if test_c is not None:
-        model_time = duration - test_c.collect_time
-        test_speed = test_c.collect_step / test_c.collect_time
+    if test_collector is not None:
+        model_time = max(0, duration - test_collector.collect_time)
+        test_speed = test_collector.collect_step / test_collector.collect_time
         result.update(
             {
-                "test_step": test_c.collect_step,
-                "test_episode": test_c.collect_episode,
-                "test_time": f"{test_c.collect_time:.2f}s",
+                "test_step": test_collector.collect_step,
+                "test_episode": test_collector.collect_episode,
+                "test_time": f"{test_collector.collect_time:.2f}s",
                 "test_speed": f"{test_speed:.2f} step/s",
                 "best_reward": best_reward,
                 "best_result": f"{best_reward:.2f} ± {best_reward_std:.2f}",
                 "duration": f"{duration:.2f}s",
                 "train_time/model": f"{model_time:.2f}s",
             }
         )
-    if train_c is not None:
-        model_time -= train_c.collect_time
-        if test_c is not None:
-            train_speed = train_c.collect_step / (duration - test_c.collect_time)
+    if train_collector is not None:
+        model_time = max(0, model_time - train_collector.collect_time)
+        if test_collector is not None:
+            train_speed = train_collector.collect_step / (
+                duration - test_collector.collect_time
+            )
         else:
-            train_speed = train_c.collect_step / duration
+            train_speed = train_collector.collect_step / duration
         result.update(
             {
-                "train_step": train_c.collect_step,
-                "train_episode": train_c.collect_episode,
-                "train_time/collector": f"{train_c.collect_time:.2f}s",
+                "train_step": train_collector.collect_step,
+                "train_episode": train_collector.collect_episode,
+                "train_time/collector": f"{train_collector.collect_time:.2f}s",
                 "train_time/model": f"{model_time:.2f}s",
                 "train_speed": f"{train_speed:.2f} step/s",
             }