allow dynamic PyObject conversion to IEnumerable when the object is a Python iterable

lostmsu · lostmsu · commit ad0d4e7940b4 · 2022-02-17T11:29:52.000-08:00
this enables foreach loops over dynamic PyObject instances closes pythonnet#1680
diff --git a/src/embed_tests/dynamic.cs b/src/embed_tests/dynamic.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Text;
 using NUnit.Framework;
 using Python.Runtime;
@@ -126,5 +127,15 @@ public void PassPyObjectInNet()
             // Compare in .NET
             Assert.IsTrue(sys.testattr1.Equals(sys.testattr2));
         }
+
+        // regression test for https://github.com/pythonnet/pythonnet/issues/1680
+        [Test]
+        public void ForEach()
+        {
+            dynamic pyList = PythonEngine.Eval("[1,2,3]");
+            var list = new List<int>();
+            foreach (int item in pyList)
+                list.Add(item);
+        }
     }
 }
diff --git a/src/runtime/PythonTypes/PyObject.cs b/src/runtime/PythonTypes/PyObject.cs
@@ -1296,6 +1296,12 @@ public override bool TryConvert(ConvertBinder binder, out object? result)
                 return converted;
             }
 
+            if (binder.Type == typeof(System.Collections.IEnumerable) && this.IsIterable())
+            {
+                result = new PyIterable(this.Reference);
+                return true;
+            }
+
             return false;
         }
 

Original file line number	Diff line number	Diff line change
`@@ -1296,6 +1296,12 @@ public override bool TryConvert(ConvertBinder binder, out object? result)`
`1296`	`1296`	`return converted;`
`1297`	`1297`	`}`
`1298`	`1298`
	`1299`	`+ if (binder.Type == typeof(System.Collections.IEnumerable) && this.IsIterable())`
	`1300`	`+ {`
	`1301`	`+ result = new PyIterable(this.Reference);`
	`1302`	`+ return true;`
	`1303`	`+ }`
	`1304`	`+`
`1299`	`1305`	`return false;`
`1300`	`1306`	`}`
`1301`	`1307`