Added ToPythonAs<T>() extension method to allow for explicit conversion using a specific type (#2330)

lostmsu · web-flow · commit 9d18a243f507 · 2024-02-28T08:36:05.000+01:00
fixes #2311
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,8 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 
 ### Added
 
+-   Added `ToPythonAs<T>()` extension method to allow for explicit conversion using a specific type. ([#2311][i2311])
+
 ### Changed
 
 ### Fixed
@@ -960,3 +962,4 @@ This version improves performance on benchmarks significantly compared to 2.3.
 [i238]: https://github.com/pythonnet/pythonnet/issues/238
 [i1481]: https://github.com/pythonnet/pythonnet/issues/1481
 [i1672]: https://github.com/pythonnet/pythonnet/pull/1672
+[i2311]: https://github.com/pythonnet/pythonnet/issues/2311
diff --git a/src/embed_tests/TestConverter.cs b/src/embed_tests/TestConverter.cs
@@ -185,6 +185,15 @@ public void RawPyObjectProxy()
             Assert.AreEqual(pyObject.DangerousGetAddressOrNull(), proxiedHandle);
         }
 
+        [Test]
+        public void GenericToPython()
+        {
+            int i = 42;
+            var pyObject = i.ToPythonAs<IConvertible>();
+            var type = pyObject.GetPythonType();
+            Assert.AreEqual(nameof(IConvertible), type.Name);
+        }
+
         // regression for https://github.com/pythonnet/pythonnet/issues/451
         [Test]
         public void CanGetListFromDerivedClass()
diff --git a/src/runtime/Converter.cs b/src/runtime/Converter.cs
@@ -133,7 +133,8 @@ internal static NewReference ToPython(object? value, Type type)
             if (EncodableByUser(type, value))
             {
                 var encoded = PyObjectConversions.TryEncode(value, type);
-                if (encoded != null) {
+                if (encoded != null)
+                {
                     return new NewReference(encoded);
                 }
             }
@@ -334,7 +335,7 @@ internal static bool ToManagedValue(BorrowedReference value, Type obType,
 
             if (obType.IsGenericType && obType.GetGenericTypeDefinition() == typeof(Nullable<>))
             {
-                if( value == Runtime.PyNone )
+                if (value == Runtime.PyNone)
                 {
                     result = null;
                     return true;
@@ -980,5 +981,11 @@ public static PyObject ToPython(this object? o)
             if (o is null) return Runtime.None;
             return Converter.ToPython(o, o.GetType()).MoveToPyObject();
         }
+
+        public static PyObject ToPythonAs<T>(this T? o)
+        {
+            if (o is null) return Runtime.None;
+            return Converter.ToPython(o, typeof(T)).MoveToPyObject();
+        }
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -133,7 +133,8 @@ internal static NewReference ToPython(object? value, Type type)`
`133`	`133`	`if (EncodableByUser(type, value))`
`134`	`134`	`{`
`135`	`135`	`var encoded = PyObjectConversions.TryEncode(value, type);`
`136`		`- if (encoded != null) {`
	`136`	`+ if (encoded != null)`
	`137`	`+ {`
`137`	`138`	`return new NewReference(encoded);`
`138`	`139`	`}`
`139`	`140`	`}`
`@@ -334,7 +335,7 @@ internal static bool ToManagedValue(BorrowedReference value, Type obType,`
`334`	`335`
`335`	`336`	`if (obType.IsGenericType && obType.GetGenericTypeDefinition() == typeof(Nullable<>))`
`336`	`337`	`{`
`337`		`- if( value == Runtime.PyNone )`
	`338`	`+ if (value == Runtime.PyNone)`
`338`	`339`	`{`
`339`	`340`	`result = null;`
`340`	`341`	`return true;`
`@@ -980,5 +981,11 @@ public static PyObject ToPython(this object? o)`
`980`	`981`	`if (o is null) return Runtime.None;`
`981`	`982`	`return Converter.ToPython(o, o.GetType()).MoveToPyObject();`
`982`	`983`	`}`
	`984`	`+`
	`985`	`+ public static PyObject ToPythonAs<T>(this T? o)`
	`986`	`+ {`
	`987`	`+ if (o is null) return Runtime.None;`
	`988`	`+ return Converter.ToPython(o, typeof(T)).MoveToPyObject();`
	`989`	`+ }`
`983`	`990`	`}`
`984`	`991`	`}`