diff --git a/tensorflow/python/framework/op_def_library.py b/tensorflow/python/framework/op_def_library.py
index 662c2c679c8..e85bba11cd1 100644
--- a/tensorflow/python/framework/op_def_library.py
+++ b/tensorflow/python/framework/op_def_library.py
@@ -195,7 +195,12 @@ def _MakeShape(v, arg_name):
                         str(v))
         break
     return v
-  return tensor_shape.as_shape(v).as_proto()
+  try:
+    return tensor_shape.as_shape(v).as_proto()
+  except TypeError as e:
+    raise TypeError("Error converting %s to a TensorShape: %s" % (arg_name, e))
+  except ValueError as e:
+    raise ValueError("Error converting %s to a TensorShape: %s" % (arg_name, e))
 
 
 def _MakeTensor(v, arg_name):
@@ -266,6 +271,7 @@ class OpDefLibrary(object):
   def __init__(self):
     self._ops = {}
 
+  # pylint: disable=invalid-name
   def add_op(self, op_def):
     """Register an OpDef. May call apply_op with the name afterwards."""
     if not isinstance(op_def, op_def_pb2.OpDef):
@@ -318,6 +324,20 @@ class OpDefLibrary(object):
       TypeError: On some errors.
       ValueError: On some errors.
     """
+    output_structure, is_stateful, op = self._apply_op_helper(
+        op_type_name, name, **keywords)
+    if output_structure:
+      outputs = op.outputs
+      res = _Restructure(ops.convert_n_to_tensor(outputs), output_structure)
+      if isinstance(res, list) and not res and is_stateful:
+        return op
+      else:
+        return res
+    else:
+      return op
+
+  def _apply_op_helper(self, op_type_name, name=None, **keywords):
+    """Implementation of apply_op that returns output_structure, op."""
     op_info = self._ops.get(op_type_name, None)
     if op_info is None:
       raise RuntimeError("Unrecognized Op name " + op_type_name)
@@ -617,8 +637,8 @@ class OpDefLibrary(object):
         if input_arg.is_ref:
           if not all(x._is_ref_dtype for x in types):  # pylint: disable=protected-access
             raise TypeError(
-                ("'%s' Op requires that input '%s' be a mutable tensor " +
-                "(e.g.: a tf.Variable)") % (op_type_name, input_name))
+                ("'%s' Op requires that input '%s' be a mutable tensor "
+                 "(e.g.: a tf.Variable)") % (op_type_name, input_name))
           input_types.extend(types)
         else:
           input_types.extend(base_types)
@@ -765,12 +785,6 @@ class OpDefLibrary(object):
         op = g.create_op(op_type_name, inputs, output_types, name=scope,
                          input_types=input_types, attrs=attr_protos,
                          op_def=op_def)
-        if output_structure:
-          outputs = op.outputs
-          res = _Restructure(ops.convert_n_to_tensor(outputs), output_structure)
-          if isinstance(res, list) and not res and op_def.is_stateful:
-            return op
-          else:
-            return res
-        else:
-          return op
+      return output_structure, op_def.is_stateful, op
+
+# pylint: enable=invalid-name
diff --git a/tensorflow/python/framework/python_op_gen.cc b/tensorflow/python/framework/python_op_gen.cc
index 090436aebf7..e7aaaeb2338 100644
--- a/tensorflow/python/framework/python_op_gen.cc
+++ b/tensorflow/python/framework/python_op_gen.cc
@@ -682,28 +682,26 @@ void GenPythonOp::AddDocStringOutputs() {
 }
 
 void GenPythonOp::AddBody(const string& prefix) {
-  AddBodyNoReturn(prefix);
-  strings::StrAppend(&result_, prefix, "return _result\n");
-}
-
-void GenPythonOp::AddBodyNoReturn(const string& prefix) {
-  string return_prefix =
+  const string apply_prefix =
       strings::StrCat(prefix, "_result = _op_def_lib.apply_op(");
-  string return_args = strings::StrCat("\"", op_def_.name(), "\", ");
-  for (size_t i = 0; i < param_names_.size(); ++i) {
-    strings::StrAppend(&return_args, param_names_[i], "=", param_names_[i],
-                       ", ");
-  }
-  strings::StrAppend(&return_args, "name=name)");
-
-  strings::StrAppend(&result_,
-                     // Wrap the arguments, and indent to the (.
-                     WordWrap(return_prefix, return_args, kRightMargin), "\n");
-
+  AddBodyNoReturn(apply_prefix);
   if (num_outs_ > 1) {
     strings::StrAppend(&result_, prefix, "_result = _", op_def_.name(),
                        "Output._make(_result)\n");
   }
+  strings::StrAppend(&result_, prefix, "return _result\n");
+}
+
+void GenPythonOp::AddBodyNoReturn(const string& apply_prefix) {
+  string args = strings::StrCat("\"", op_def_.name(), "\", ");
+  for (size_t i = 0; i < param_names_.size(); ++i) {
+    strings::StrAppend(&args, param_names_[i], "=", param_names_[i], ", ");
+  }
+  strings::StrAppend(&args, "name=name)");
+
+  strings::StrAppend(&result_,
+                     // Wrap the arguments, and indent to the (.
+                     WordWrap(apply_prefix, args, kRightMargin), "\n");
 }
 
 }  // namespace python_op_gen_internal
diff --git a/tensorflow/python/framework/python_op_gen_internal.h b/tensorflow/python/framework/python_op_gen_internal.h
index d588f362d82..92237ac81a2 100644
--- a/tensorflow/python/framework/python_op_gen_internal.h
+++ b/tensorflow/python/framework/python_op_gen_internal.h
@@ -38,6 +38,8 @@ string AttrValueToPython(const string& type, const AttrValue& value,
 
 void GenerateLowerCaseOpName(const string& str, string* result);
 
+string DataTypeToPython(DataType dtype, const string& dtype_module);
+
 class GenPythonOp {
  public:
   GenPythonOp(const OpDef& op_def, const string& function_name);
@@ -59,11 +61,11 @@ class GenPythonOp {
   void AddOutputGlobals();
   void AddDocStringOutputs();
   void AddBody(const string& prefix);
-  void AddBodyNoReturn(const string& prefix);
+  void AddBodyNoReturn(const string& apply_prefix);
 
   // From constructor arguments
   const OpDef& op_def_;
-  const string& function_name_;
+  const string function_name_;
   const int num_outs_;
 
   // Return value from Code() is prelude_ + result_.