build: Make sympy an optional dependency

onnxruntime/python/tools/symbolic_shape_infer.py

@@ -7,7 +7,12 @@
 
 import numpy as np
 import onnx
-import sympy
+
+try:
+    import sympy
+except ImportError:
+    raise ImportError("sympy is required for symbolic shape inference. Install with: pip install sympy") from None
+
 from onnx import helper, numpy_helper, shape_inference
 from packaging import version
 

requirements.txt

@@ -2,4 +2,3 @@ flatbuffers
 numpy >= 1.21.6
 packaging
 protobuf
-sympy

setup.py

@@ -841,21 +841,26 @@ def save_build_and_package_info(package_name, version_number, cuda_version, qnn_
 
 save_build_and_package_info(package_name, version_number, cuda_version, qnn_version)
 
-extras_require = {}
+# sympy is optional - only needed for symbolic shape inference
+extras_require = {
+    "symbolic": ["sympy"],
+}
 if package_name == "onnxruntime-gpu" and cuda_major_version:
     # Determine cufft version: CUDA 13 uses cufft 12, CUDA 12 uses cufft 11
     cufft_version = "12.0" if cuda_major_version == "13" else "11.0"
-    extras_require = {
-        "cuda": [
-            f"nvidia-cuda-nvrtc-cu{cuda_major_version}~={cuda_major_version}.0",
-            f"nvidia-cuda-runtime-cu{cuda_major_version}~={cuda_major_version}.0",
-            f"nvidia-cufft-cu{cuda_major_version}~={cufft_version}",
-            f"nvidia-curand-cu{cuda_major_version}~=10.0",
-        ],
-        "cudnn": [
-            f"nvidia-cudnn-cu{cuda_major_version}~=9.0",
-        ],
-    }
+    extras_require.update(
+        {
+            "cuda": [
+                f"nvidia-cuda-nvrtc-cu{cuda_major_version}~={cuda_major_version}.0",
+                f"nvidia-cuda-runtime-cu{cuda_major_version}~={cuda_major_version}.0",
+                f"nvidia-cufft-cu{cuda_major_version}~={cufft_version}",
+                f"nvidia-curand-cu{cuda_major_version}~=10.0",
+            ],
+            "cudnn": [
+                f"nvidia-cudnn-cu{cuda_major_version}~=9.0",
+            ],
+        }
+    )
 
 setup(
     name=package_name,