Add low-quality experience filter operator #470 (#473)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: AdnanQureshi3

trinity/buffer/operators/__init__.py

@@ -9,6 +9,7 @@
         "reward_shaping_mapper": "trinity.buffer.operators.mappers.reward_shaping_mapper.RewardShapingMapper",
         "pass_rate_calculator": "trinity.buffer.operators.mappers.pass_rate_calculator.PassRateCalculator",
         "data_juicer": "trinity.buffer.operators.data_juicer_operator.DataJuicerOperator",
+        "invalid_reward_filter": "trinity.buffer.operators.filters.reward_filter.InvalidRewardFilter",
     },
 )
 

trinity/buffer/operators/filters/reward_filter.py

@@ -50,3 +50,19 @@ def process(self, exps: List[Experience]) -> Tuple[List[Experience], dict]:
         final_count = len(result_exps)
         metrics["filtered_count"] = original_count - final_count
         return result_exps, metrics
+
+
+class InvalidRewardFilter(ExperienceOperator):
+    """
+    Filters out experiences with invalid reward values.
+
+    Note: This operator assumes that rewards are already computed and stored in the
+    Experience object.Any experience with a missing (`None`) or invalid (`NaN`)
+    reward is removed to prevent low-quality data from entering the training
+    pipeline.
+    """
+
+    def process(self, exps: List[Experience]) -> Tuple[List[Experience], dict]:
+        kept = [e for e in exps if e.reward is not None and e.reward == e.reward]
+
+        return kept, {"filtered_count": len(exps) - len(kept)}