Add pred, export and val callbacks (#126)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

ultralytics/yolo/utils/callbacks/base.py

@@ -1,3 +1,7 @@
+# Ultralytics YOLO base callbacks
+
+
+# Trainer callbacks ----------------------------------------------------------------------------------------------------
 def on_pretrain_routine_start(trainer):
     pass
 
@@ -34,26 +38,6 @@ def on_train_epoch_end(trainer):
     pass
 
 
-def on_val_start(trainer):
-    pass
-
-
-def on_val_batch_start(trainer):
-    pass
-
-
-def on_val_image_end(trainer):
-    pass
-
-
-def on_val_batch_end(trainer):
-    pass
-
-
-def on_val_end(trainer):
-    pass
-
-
 def on_fit_epoch_end(trainer):
     pass
 
@@ -74,7 +58,51 @@ def teardown(trainer):
     pass
 
 
+# Validator callbacks --------------------------------------------------------------------------------------------------
+def on_val_start(validator):
+    pass
+
+
+def on_val_batch_start(validator):
+    pass
+
+
+def on_val_batch_end(validator):
+    pass
+
+
+def on_val_end(validator):
+    pass
+
+
+# Predictor callbacks --------------------------------------------------------------------------------------------------
+def on_predict_start(predictor):
+    pass
+
+
+def on_predict_batch_start(predictor):
+    pass
+
+
+def on_predict_batch_end(predictor):
+    pass
+
+
+def on_predict_end(predictor):
+    pass
+
+
+# Exporter callbacks ---------------------------------------------------------------------------------------------------
+def on_export_start(exporter):
+    pass
+
+
+def on_export_end(exporter):
+    pass
+
+
 default_callbacks = {
+    # Run in trainer
     'on_pretrain_routine_start': on_pretrain_routine_start,
     'on_pretrain_routine_end': on_pretrain_routine_end,
     'on_train_start': on_train_start,
@@ -84,16 +112,27 @@ default_callbacks = {
     'on_before_zero_grad': on_before_zero_grad,
     'on_train_batch_end': on_train_batch_end,
     'on_train_epoch_end': on_train_epoch_end,
-    'on_val_start': on_val_start,
-    'on_val_batch_start': on_val_batch_start,
-    'on_val_image_end': on_val_image_end,
-    'on_val_batch_end': on_val_batch_end,
-    'on_val_end': on_val_end,
     'on_fit_epoch_end': on_fit_epoch_end,  # fit = train + val
     'on_model_save': on_model_save,
     'on_train_end': on_train_end,
     'on_params_update': on_params_update,
-    'teardown': teardown}
+    'teardown': teardown,
+
+    # Run in validator
+    'on_val_start': on_val_start,
+    'on_val_batch_start': on_val_batch_start,
+    'on_val_batch_end': on_val_batch_end,
+    'on_val_end': on_val_end,
+
+    # Run in predictor
+    'on_predict_start': on_predict_start,
+    'on_predict_batch_start': on_predict_batch_start,
+    'on_predict_batch_end': on_predict_batch_end,
+    'on_predict_end': on_predict_end,
+
+    # Run in exporter
+    'on_export_start': on_export_start,
+    'on_export_end': on_export_end}
 
 
 def add_integration_callbacks(trainer):