fixed. sp.writeToString Unicode error

Author: Lupino

bindings/py/cpp_src/bindings/algorithms/py_SpatialPooler.cpp

@@ -246,9 +246,9 @@ Argument wrapAround boolean value that determines whether or not inputs
         py_SpatialPooler.def("setMinPctOverlapDutyCycles", &SpatialPooler::setMinPctOverlapDutyCycles);
 
         // loadFromString
-        py_SpatialPooler.def("loadFromString", [](SpatialPooler& self, const std::string& inString)
+        py_SpatialPooler.def("loadFromString", [](SpatialPooler& self, const py::bytes& inString)
         {
-            std::istringstream inStream(inString);
+            std::stringstream inStream(inString.cast<std::string>());
             self.load(inStream);
         });
 
@@ -261,7 +261,7 @@ Argument wrapAround boolean value that determines whether or not inputs
 
             self.save(os);
 
-            return os.str();
+            return py::bytes( os.str() );
         });
 
         // compute

bindings/py/tests/algorithms/spatial_pooler_test.py

@@ -184,7 +184,8 @@ def testNupicSpatialPoolerSavingToString(self):
     sp = SP()
     s = sp.writeToString()
 
-    sp2 = sp.readFromString(s)
+    sp2 = SP(columnDimensions=[32, 32])
+    sp2.loadFromString(s)
 
     self.assertEqual(sp.getNumColumns(), sp2.getNumColumns(),
                      "NuPIC SpatialPooler write to/read from string failed.")