python: support Python list for cv::Range

modules/python/src2/cv2.cpp

@@ -819,6 +819,40 @@ bool pyopencv_to(PyObject* obj, Range& r, const char* name)
     CV_UNUSED(name);
     if(!obj || obj == Py_None)
         return true;
+    while (PySequence_Check(obj))
+    {
+        PyObject *fi = PySequence_Fast(obj, name);
+        if (fi == NULL)
+            break;
+        if (2 != PySequence_Fast_GET_SIZE(fi))
+        {
+            failmsg("Range value for argument '%s' is longer than 2", name);
+            Py_DECREF(fi);
+            return false;
+        }
+        {
+            PyObject *item = PySequence_Fast_GET_ITEM(fi, 0);
+            if (PyInt_Check(item)) {
+                r.start = (int)PyInt_AsLong(item);
+            } else {
+                failmsg("Range.start value for argument '%s' is not integer", name);
+                Py_DECREF(fi);
+                break;
+            }
+        }
+        {
+            PyObject *item = PySequence_Fast_GET_ITEM(fi, 1);
+            if (PyInt_Check(item)) {
+                r.end = (int)PyInt_AsLong(item);
+            } else {
+                failmsg("Range.end value for argument '%s' is not integer", name);
+                Py_DECREF(fi);
+                break;
+            }
+        }
+        Py_DECREF(fi);
+        return true;
+    }
     if(PyObject_Size(obj) == 0)
     {
         r = Range::all();