make emotion module optional to avoid pytorch dependency

uniface/__init__.py

@@ -21,7 +21,11 @@ from uniface.log import Logger, enable_logging
 from uniface.model_store import verify_model_weights
 from uniface.visualization import draw_detections
 
-from .attribute import AgeGender, Emotion
+from .attribute import AgeGender
+try:
+    from .attribute import Emotion
+except ImportError:
+    Emotion = None  # PyTorch not installed
 from .detection import SCRFD, RetinaFace, create_detector, detect_faces, list_available_detectors
 from .landmark import Landmark106, create_landmarker
 from .recognition import ArcFace, MobileFace, SphereFace, create_recognizer

uniface/attribute/__init__.py

@@ -6,10 +6,17 @@ from typing import Dict, Any, List, Union
 import numpy as np
 
 from uniface.attribute.age_gender import AgeGender
-from uniface.attribute.emotion import Emotion
 from uniface.attribute.base import Attribute
 from uniface.constants import AgeGenderWeights, DDAMFNWeights
 
+# Emotion requires PyTorch - make it optional
+try:
+    from uniface.attribute.emotion import Emotion
+    _EMOTION_AVAILABLE = True
+except ImportError:
+    Emotion = None
+    _EMOTION_AVAILABLE = False
+
 # Public API for the attribute module
 __all__ = [
     "AgeGender",
@@ -21,9 +28,12 @@ __all__ = [
 # A mapping from model enums to their corresponding attribute classes
 _ATTRIBUTE_MODELS = {
     **{model: AgeGender for model in AgeGenderWeights},
-    **{model: Emotion for model in DDAMFNWeights}
 }
 
+# Add Emotion models only if PyTorch is available
+if _EMOTION_AVAILABLE:
+    _ATTRIBUTE_MODELS.update({model: Emotion for model in DDAMFNWeights})
+
 
 def create_attribute_predictor(
     model_name: Union[AgeGenderWeights, DDAMFNWeights],