Support special step customization (#123)

* Support special step customization

* lint

rdagent/app/qlib_rd_loop/factor_w_sc.py

@@ -2,16 +2,28 @@
 Factor workflow with session control
 """
 
+from typing import Any
+
 import fire
 
 from rdagent.app.qlib_rd_loop.conf import FACTOR_PROP_SETTING
 from rdagent.components.workflow.rd_loop import RDLoop
 from rdagent.core.exception import FactorEmptyError
+from rdagent.log import rdagent_logger as logger
 
 
 class FactorRDLoop(RDLoop):
     skip_loop_error = (FactorEmptyError,)
 
+    def exp_gen(self, prev_out: dict[str, Any]):
+        with logger.tag("r"):  # research
+            exp = self.hypothesis2experiment.convert(prev_out["propose"], self.trace)
+            if exp is None:
+                logger.error(f"Factor extraction failed.")
+                raise FactorEmptyError("Factor extraction failed.")
+            logger.log_object(exp.sub_tasks, tag="experiment generation")
+        return exp
+
 
 def main(path=None, step_n=None):
     """

rdagent/utils/workflow.py

@@ -35,7 +35,10 @@ class LoopMeta(type):
         steps = LoopMeta._get_steps(bases)  # all the base classes of parents
         for name, attr in attrs.items():
             if not name.startswith("__") and isinstance(attr, Callable):
-                steps.append(name)
+                if name not in steps:
+                    # NOTE: if we override the step in the subclass
+                    # Then it is not the new step. So we skip it.
+                    steps.append(name)
         attrs["steps"] = steps
         return super().__new__(cls, clsname, bases, attrs)