patch_attrs helper

src/compressed_tensors/utils/helpers.py

@@ -16,7 +16,17 @@
 import warnings
 from functools import wraps
 from types import MappingProxyType
-from typing import TYPE_CHECKING, Any, Callable, Dict, List, Mapping, Optional, TypeVar
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    List,
+    Mapping,
+    Optional,
+    TypeVar,
+)
 
 import numpy
 import torch
@@ -44,6 +54,7 @@
     "pack_bitmasks",
     "unpack_bitmasks",
     "patch_attr",
+    "patch_attrs",
     "ParameterizedDefaultDict",
     "get_num_attn_heads",
     "get_num_kv_heads",
@@ -368,6 +379,34 @@ def patch_attr(base: object, attr: str, value: Any):
             delattr(base, attr)
 
 
+@contextlib.contextmanager
+def patch_attrs(bases: Iterable[Any], attr: str, values: Iterable[Any]):
+    """
+    Same as `patch_attr` but for a list of objects to patch
+    Patch attribute for a list of objects with list of values.
+    Original values are restored upon exit
+
+    :param bases: objects which has the attribute to patch
+    :param attr: name of the the attribute to patch
+    :param values: used to replace original values. Must be same
+        length as bases
+
+    Usage:
+    >>> from types import SimpleNamespace
+    >>> obj1 = SimpleNamespace()
+    >>> obj2 = SimpleNamespace()
+    >>> with patch_attr([obj1, obj2], "attribute", ["value1", "value2"]):
+    ...     assert obj1.attribute == "value1"
+    ...     assert obj2.attribute == "value2"
+    >>> assert not hasattr(obj1, "attribute")
+    >>> assert not hasattr(obj2, "attribute")
+    """
+    with contextlib.ExitStack() as stack:
+        for base, value in zip(bases, values):
+            stack.enter_context(patch_attr(base, attr, value))
+        yield
+
+
 class ParameterizedDefaultDict(dict):
     """
     Similar to `collections.DefaultDict`, but upon fetching a key which is missing,

tests/test_utils/test_helpers.py

@@ -21,6 +21,7 @@
     ParameterizedDefaultDict,
     load_compressed,
     patch_attr,
+    patch_attrs,
     save_compressed,
     save_compressed_model,
 )
@@ -176,6 +177,23 @@ def test_patch_attr():
     assert not hasattr(obj, "attribute")
 
 
+def test_patch_attrs():
+    num_objs = 4
+    objs = [SimpleNamespace() for _ in range(num_objs)]
+    for idx, obj in enumerate(objs):
+        if idx % 2 == 0:
+            obj.attribute = f"original_{idx}"
+    with patch_attrs(objs, "attribute", [f"patched_{idx}" for idx in range(num_objs)]):
+        for idx, obj in enumerate(objs):
+            assert obj.attribute == f"patched_{idx}"
+            obj.attribute = "modified"
+    for idx, obj in enumerate(objs):
+        if idx % 2 == 0:
+            assert obj.attribute == f"original_{idx}"
+        else:
+            assert not hasattr(obj, "attribute")
+
+
 def test_parameterized_default_dict():
     def add_one(value):
         return value + 1