add reverse impl.

Author: GdoongMathew

src/lightning/pytorch/loggers/utilities.py

@@ -13,9 +13,9 @@
 # limitations under the License.
 """Utilities for loggers."""
 
-from collections.abc import ItemsView, KeysView, Mapping, ValuesView
+from collections.abc import ItemsView, Iterable, KeysView, Mapping, ValuesView
 from pathlib import Path
-from typing import Any, Optional, TypeVar, Union
+from typing import Any, Optional, SupportsIndex, TypeVar, Union
 
 from torch import Tensor
 from typing_extensions import Self
@@ -110,7 +110,7 @@ def _log_hyperparams(trainer: "pl.Trainer") -> None:
 class _ListMap(list[_T]):
     """A hybrid container for loggers allowing both index and name access."""
 
-    def __init__(self, loggers: Union[list[_T], Mapping[str, _T]] = None):
+    def __init__(self, loggers: Union[Iterable[_T], Mapping[str, _T]] = None):
         if isinstance(loggers, Mapping):
             # super inits list with values
             if any(not isinstance(x, str) for x in loggers):
@@ -145,7 +145,7 @@ def __iadd__(self, other: Union[list[_T], Self]) -> Self:
         # todo
         return list.__iadd__(self, other)
 
-    def __setitem__(self, key: Union[int, slice, str], value: _T) -> None:
+    def __setitem__(self, key: Union[SupportsIndex, slice, str], value: _T) -> None:
         if isinstance(key, (int, slice)):
             # replace element by index
             return list.__setitem__(self, key, value)
@@ -192,7 +192,7 @@ def items(self) -> ItemsView[str, _T]:
         return d.items()
 
     # --- List and Dict interface ---
-    def pop(self, key: Union[int, str] = -1, default: Optional[Any] = None) -> _T:
+    def pop(self, key: Union[SupportsIndex, str] = -1, default: Optional[Any] = None) -> _T:
         if isinstance(key, int):
             ret = list.pop(self, key)
             for str_key, idx in list(self._dict.items()):
@@ -210,3 +210,15 @@ def pop(self, key: Union[int, str] = -1, default: Optional[Any] = None) -> _T:
     def __repr__(self) -> str:
         ret = super().__repr__()
         return f"_ListMap({ret}, keys={list(self._dict.keys())})"
+
+    def __reversed__(self) -> Iterable[_T]:
+        return reversed(list(self))
+
+    def reverse(self) -> None:
+        for key, idx in self._dict.items():
+            self._dict[key] = len(self) - 1 - idx
+        list.reverse(self)
+
+    def clear(self):
+        self._dict.clear()
+        list.clear(self)

tests/tests_pytorch/loggers/test_utilities.py

@@ -122,6 +122,30 @@ def test_listmap_remove():
     assert 2 not in lm
 
 
+def test_listmap_reverse():
+    """Test reversing the collection."""
+    lm = _ListMap({"1": 1, "2": 2, "3": 3})
+    lm.reverse()
+    assert lm == [3, 2, 1]
+    for (key, value), expected in zip(lm.items(), [("1", 1), ("2", 2), ("3", 3)]):
+        assert (key, value) == expected
+
+
+def test_listmap_reversed():
+    """Test reversed iterator of the collection."""
+    lm = _ListMap({"1": 1, "2": 2, "3": 3})
+    rev_lm = list(reversed(lm))
+    assert rev_lm == [3, 2, 1]
+
+
+def test_listmap_clear():
+    """Test clearing the collection."""
+    lm = _ListMap({"1": 1, "2": 2, "3": 3})
+    lm.clear()
+    assert len(lm) == 0
+    assert len(lm.keys()) == 0
+
+
 # Dict type properties tests
 def test_listmap_keys():
     lm = _ListMap({