Fix torch import guards in rtdetr_pose to allow execution without torch installed

rtdetr_pose/rtdetr_pose/backbone_interface.py

@@ -3,7 +3,16 @@
 from abc import ABC, abstractmethod
 from typing import List, Sequence
 
-from torch import Tensor, nn
+try:
+    from torch import Tensor, nn
+except ImportError:  # pragma: no cover
+    from types import SimpleNamespace
+
+    class _NNModuleStub:  # type: ignore[no-redef]
+        pass
+
+    Tensor = None  # type: ignore[assignment,misc]
+    nn = SimpleNamespace(Module=_NNModuleStub)  # type: ignore[assignment]
 
 
 class BaseBackbone(nn.Module, ABC):

rtdetr_pose/rtdetr_pose/backbone_projector.py

@@ -2,7 +2,13 @@
 
 from typing import Iterable, Sequence
 
-from torch import Tensor, nn
+try:
+    from torch import Tensor, nn
+except ImportError:  # pragma: no cover
+    from types import SimpleNamespace
+
+    Tensor = None  # type: ignore[assignment,misc]
+    nn = SimpleNamespace(Module=object)  # type: ignore[assignment]
 
 
 class BackboneProjector(nn.Module):

rtdetr_pose/rtdetr_pose/models/backbones/blocks.py

@@ -2,8 +2,14 @@
 
 from typing import Optional
 
-import torch
-from torch import nn
+try:
+    import torch
+    from torch import nn
+except ImportError:  # pragma: no cover
+    from types import SimpleNamespace
+
+    torch = None  # type: ignore[assignment]
+    nn = SimpleNamespace(Module=object)  # type: ignore[assignment]
 
 
 def _normalize_activation_name(name: str) -> str:

rtdetr_pose/rtdetr_pose/models/backbones/csp_backbones.py

@@ -2,7 +2,13 @@
 
 from typing import Sequence
 
-from torch import Tensor, nn
+try:
+    from torch import Tensor, nn
+except ImportError:  # pragma: no cover
+    from types import SimpleNamespace
+
+    Tensor = None  # type: ignore[assignment,misc]
+    nn = SimpleNamespace(Module=object)  # type: ignore[assignment]
 
 from ...backbone_interface import BaseBackbone
 from .blocks import CSPBlock, ConvNormAct, SPPF

rtdetr_pose/rtdetr_pose/models/backbones/torchvision_backbones.py

@@ -2,7 +2,10 @@
 
 from typing import Sequence
 
-from torch import Tensor
+try:
+    from torch import Tensor
+except ImportError:  # pragma: no cover
+    Tensor = None  # type: ignore[assignment,misc]
 
 from ...backbone_interface import BaseBackbone
 from .registry import register_backbone