changes requested

Author: direkkakkar319-ops

pyaptamer/mcts/_algorithm.py

@@ -24,8 +24,8 @@ class MCTS(BaseObject):
     ----------
     states : list[str], optional, default=None
         Possible values for the nodes. Underscores indicate whether the values are
-        supposed to be prepended or appended to the sequence. Must be non-empty and
-        contain unique entries.
+        supposed to be prepended or appended to the sequence. If None or empty,
+        defaults to the standard RNA nucleotide states. Must contain unique entries.
     depth : int, optional, default=20
         Maximum depth of the search tree, also the length of the generated
         sequences. Must be >= 1.
@@ -34,6 +34,15 @@ class MCTS(BaseObject):
     experiment : BaseAptamerEval, optional, default=None
         An instance of an experiment class definingthe goal function for the algorithm.
 
+    Raises
+    ------
+    ValueError
+        If ``depth`` is less than 1.
+    ValueError
+        If ``n_iterations`` is less than 1.
+    ValueError
+        If ``states`` contains duplicate entries.
+
     Attributes
     ----------
     root : TreeNode
@@ -81,10 +90,8 @@ def __init__(
         if n_iterations < 1:
             raise ValueError(f"`n_iterations` must be >= 1, got {n_iterations}.")
 
-        if states is None:
+        if not states:
             states = ["A_", "C_", "G_", "U_", "_A", "_C", "_G", "_U"]
-        elif not states:
-            raise ValueError("`states` must contain at least one entry.")
         elif len(states) != len(set(states)):
             raise ValueError("`states` must contain unique entries.")
 

pyaptamer/mcts/tests/test_mcts.py

@@ -253,10 +253,11 @@ def test_init_invalid_iterations(self, n_iterations):
         with pytest.raises(ValueError, match=r"`n_iterations` must be >= 1"):
             MCTS(n_iterations=n_iterations)
 
-    def test_init_empty_states(self):
-        """Check an empty search space is rejected early."""
-        with pytest.raises(ValueError, match=r"`states` must contain at least one"):
-            MCTS(states=[])
+    @pytest.mark.parametrize("states", [None, []])
+    def test_init_empty_or_none_states_defaults(self, states):
+        """Check that None or empty states default to the standard nucleotide set."""
+        mcts = MCTS(states=states)
+        assert mcts.states == ["A_", "C_", "G_", "U_", "_A", "_C", "_G", "_U"]
 
     def test_init_duplicate_states(self):
         """Check duplicate states are rejected early."""