fix default and fix attribute traversal for layers

src/axolotl/utils/callbacks/lisa.py

@@ -1,5 +1,12 @@
-"""module for LISA"""
-import ast
+"""
+module for LISA
+
+Adapted from https://github.com/OptimalScale/LMFlow/pull/701 for HF transformers & Axolotl
+Arxiv: https://arxiv.org/abs/2403.17919
+License: Apache 2.0
+"""
+
+from functools import reduce
 from typing import TYPE_CHECKING
 
 import numpy as np
@@ -22,16 +29,18 @@ def lisa_callback_factory(trainer: "AxolotlTrainer"):
             self.layers_attribute = layers_attribute
             self.trainer = trainer
 
+            reduce(getattr, self.layers_attribute.split("."), self.trainer.model)
+
             self.total_layers = len(
-                ast.literal_eval("self.trainer.model." + self.layers_attribute)
+                reduce(getattr, self.layers_attribute.split("."), self.trainer.model)
             )
             self.freeze_all_layers()
             self.active_layers_indices = []
 
         def freeze_all_layers(self):
-            layers = ast.literal_eval(
-                "self.trainer.model." + self.layers_attribute
-            )  # Dynamically execute to get layers
+            layers = reduce(
+                getattr, self.layers_attribute.split("."), self.trainer.model
+            )
             for layer in layers:
                 for param in layer.parameters():
                     param.requires_grad = False
@@ -48,9 +57,9 @@ def lisa_callback_factory(trainer: "AxolotlTrainer"):
             self.freeze_all_layers()
 
             # Randomly select n_layers to activate
-            layers = ast.literal_eval(
-                "self.trainer.model" + self.layers_attribute
-            )  # Re-fetch layer references
+            layers = reduce(
+                getattr, self.layers_attribute.split("."), self.trainer.model
+            )
             self.active_layers_indices = np.random.choice(
                 range(self.total_layers), self.n_layers, replace=False
             )

src/axolotl/utils/config/models/input/v0_4_1/__init__.py

@@ -382,7 +382,7 @@ class LISAConfig(BaseModel):
         metadata={"help": "how often to switch layers in LISA"},
     )
     lisa_layers_attribute: Optional[str] = Field(
-        default="",
+        default="model.layers",
         metadata={"help": "path under the model to access the layers"},
     )