fix: Fixed some bugs introduced during refactoring. (#167)

* Fixed some bugs introduced during refactoring.

* fix a minor bug

* build factor source data (price and volumns) from qlib if no source data is provided by the user (#168)

* Fixed some bugs introduced during refactoring.

* fix a small bug

* fix a small bug

---------

Co-authored-by: Xu Yang <peteryang@vip.qq.com>

rdagent/utils/workflow.py

@@ -24,7 +24,13 @@ class LoopMeta(type):
     @staticmethod
     def _get_steps(bases):
         """
-        get all the `steps` of base classes and combine them to a single one.
+        Recursively get all the `steps` from the base classes and combine them into a single list.
+
+        Args:
+            bases (tuple): A tuple of base classes.
+
+        Returns:
+            List[Callable]: A list of steps combined from all base classes.
         """
         steps = []
         for base in bases:
@@ -34,7 +40,17 @@ class LoopMeta(type):
         return steps
 
     def __new__(cls, clsname, bases, attrs):
-        # move custommized steps into steps
+        """
+        Create a new class with combined steps from base classes and current class.
+
+        Args:
+            clsname (str): Name of the new class.
+            bases (tuple): Base classes.
+            attrs (dict): Attributes of the new class.
+
+        Returns:
+            LoopMeta: A new instance of LoopMeta.
+        """
         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):