Adding python bindings for VtArray<SdfPathExpression> objects.

Without these additions, it is not possible to use python to get or set
attributes or metadata of type Sdf.ValueTypeNames.PathExpressionArray.

(Internal change: 2358305)

Author: marktucker

pxr/usd/sdf/CMakeLists.txt

@@ -131,6 +131,7 @@ pxr_library(sdf
         module.cpp
         wrapArrayAssetPath.cpp
         wrapArrayPath.cpp
+        wrapArrayPathExpression.cpp
         wrapArrayTimeCode.cpp
         wrapAssetPath.cpp
         wrapAttributeSpec.cpp
@@ -193,6 +194,7 @@ pxr_test_scripts(
     testenv/testSdfPath2.py
     testenv/testSdfPath2Construct.py
     testenv/testSdfPathExpression.py
+    testenv/testSdfPathExpressionArray.py
     testenv/testSdfPayload.py
     testenv/testSdfPrim.py
     testenv/testSdfReference.py
@@ -469,6 +471,11 @@ pxr_register_test(testSdfPathExpression_Cpp
     COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testSdfPathExpression_Cpp"
 )
 
+pxr_register_test(testSdfPathExpressionArray
+    PYTHON
+    COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testSdfPathExpressionArray"
+)
+
 pxr_register_test(testSdfParsing
     PYTHON
     COMMAND "${CMAKE_INSTALL_PREFIX}/tests/testSdfParsing"

pxr/usd/sdf/module.cpp

@@ -14,6 +14,7 @@ TF_WRAP_MODULE
 {
     TF_WRAP( ArrayAssetPath );
     TF_WRAP( ArrayPath );
+    TF_WRAP( ArrayPathExpression );
     TF_WRAP( ArrayTimeCode );
     TF_WRAP( AssetPath );
     TF_WRAP( ChangeBlock );

pxr/usd/sdf/testenv/testSdfPathExpressionArray.py

@@ -0,0 +1,31 @@
+#!/pxrpythonsubst
+#
+# Copyright 2025 Pixar
+#
+# Licensed under the terms set forth in the LICENSE.txt file available at
+# https://openusd.org/license.
+
+from pxr import Sdf, Tf
+import sys, unittest
+
+MatchEval = Sdf._MakeBasicMatchEval
+
+class TestSdfPathExpressionArray(unittest.TestCase):
+
+    def test_Basics(self):
+        # Create arrays
+        exprs1 = Sdf.PathExpressionArray((Sdf.PathExpression('/foo'),
+                                         Sdf.PathExpression('/bar')))
+        with self.assertRaises(TypeError,
+            msg="Implicit conversions from string should fail"):
+            exprs2 = Sdf.PathExpressionArray(('/foo', '/bar'))
+
+        # Simple use of PathExpressionArray attributes.
+        l = Sdf.Layer.CreateAnonymous()
+        p = Sdf.CreatePrimInLayer(l, '/foo')
+        a = Sdf.AttributeSpec(p, 'a', Sdf.ValueTypeNames.PathExpressionArray)
+        a.default = (Sdf.PathExpression('/foo'), Sdf.PathExpression('/bar'))
+        self.assertEqual(a.default, exprs1)
+
+if __name__ == '__main__':
+    unittest.main()

pxr/usd/sdf/wrapArrayPathExpression.cpp

@@ -0,0 +1,34 @@
+//
+// Copyright 2025 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#include "pxr/pxr.h"
+#include "pxr/usd/sdf/pathExpression.h"
+#include "pxr/base/vt/array.h"
+#include "pxr/base/vt/wrapArray.h"
+#include "pxr/base/vt/valueFromPython.h"
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+namespace Vt_WrapArray {
+    template <>
+    std::string GetVtArrayName< VtArray<SdfPathExpression> >() {
+        return "PathExpressionArray";
+    }
+}
+
+template<>
+SdfPathExpression VtZero() {
+    return SdfPathExpression();
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE
+
+PXR_NAMESPACE_USING_DIRECTIVE
+
+void wrapArrayPathExpression() {
+    VtWrapArray<VtArray<SdfPathExpression> >();
+    VtValueFromPythonLValue<VtArray<SdfPathExpression> >();
+}

pxr/usd/sdf/wrapPathExpression.cpp

@@ -13,6 +13,7 @@
 #include "pxr/base/tf/pyEnum.h"
 #include "pxr/base/tf/pyFunction.h"
 #include "pxr/base/tf/pyUtils.h"
+#include "pxr/base/vt/wrapArray.h"
 
 #include "pxr/usd/sdf/pathExpression.h"
 #include "pxr/usd/sdf/pathExpressionEval.h"
@@ -33,6 +34,11 @@ using PathExpr = SdfPathExpression;
 using ExpressionReference = PathExpr::ExpressionReference;
 using PathPattern = PathExpr::PathPattern;
 
+TF_REGISTRY_FUNCTION(VtValue)
+{
+    VtRegisterValueCastsFromPythonSequencesToArray<SdfPathExpression>();
+}
+
 static std::string
 _Repr(SdfPathExpression const &self) {
     if (!self) {
@@ -199,6 +205,7 @@ void wrapPathExpression()
         .def(self == self)
         .def(self != self)
         ;
+
     VtValueFromPython<SdfPathExpression>();
 
     TfPyWrapEnum<PathExpr::Op>();