diff --git a/tensorflow/python/framework/python_op_gen.cc b/tensorflow/python/framework/python_op_gen.cc
index a423d8bb4cc..64be2c70a11 100644
--- a/tensorflow/python/framework/python_op_gen.cc
+++ b/tensorflow/python/framework/python_op_gen.cc
@@ -482,8 +482,8 @@ static string GetPythonOp(const OpDef& op_def, bool is_hidden, string op_name) {
 
   // Prepare a NamedTuple type to hold the outputs, if there are multiple
   if (num_outs > 1) {
-    const string tuple_type_prefix =
-        strings::StrCat("_", op_def.name(), "Output = collections.namedtuple(");
+    const string tuple_type_prefix = strings::StrCat(
+        "_", op_def.name(), "Output = _collections.namedtuple(");
     const string tuple_type_suffix = strings::StrCat(
         "\"", op_def.name(), "\", ", lower_op_name_outputs, ")");
     strings::Appendf(
@@ -656,18 +656,18 @@ string GetPythonOps(const OpList& ops, const std::vector<string>& hidden_ops,
 This file is MACHINE GENERATED! Do not edit.
 """
 
-import collections
+import collections as _collections
 
-from google.protobuf import text_format
+from google.protobuf import text_format as _text_format
 
-from tensorflow.core.framework import op_def_pb2
+from tensorflow.core.framework import op_def_pb2 as _op_def_pb2
 
 # Needed to trigger the call to _set_call_cpp_shape_fn.
-from tensorflow.python.framework import common_shapes
+from tensorflow.python.framework import common_shapes as _common_shapes
 
-from tensorflow.python.framework import op_def_registry
-from tensorflow.python.framework import ops
-from tensorflow.python.framework import op_def_library
+from tensorflow.python.framework import op_def_registry as _op_def_registry
+from tensorflow.python.framework import ops as _ops
+from tensorflow.python.framework import op_def_library as _op_def_library
 )");
 
   // We'll make a copy of ops that filters out descriptions.
@@ -699,7 +699,7 @@ from tensorflow.python.framework import op_def_library
                        GetPythonOp(op_def, is_hidden, lower_case_name));
 
     if (!require_shapes) {
-      strings::Appendf(&result, "ops.RegisterShape(\"%s\")(None)\n",
+      strings::Appendf(&result, "_ops.RegisterShape(\"%s\")(None)\n",
                        op_def.name().c_str());
     }
 
@@ -709,10 +709,10 @@ from tensorflow.python.framework import op_def_library
   }
 
   strings::Appendf(&result, R"(def _InitOpDefLibrary():
-  op_list = op_def_pb2.OpList()
-  text_format.Merge(_InitOpDefLibrary.op_list_ascii, op_list)
-  op_def_registry.register_op_list(op_list)
-  op_def_lib = op_def_library.OpDefLibrary()
+  op_list = _op_def_pb2.OpList()
+  _text_format.Merge(_InitOpDefLibrary.op_list_ascii, op_list)
+  _op_def_registry.register_op_list(op_list)
+  op_def_lib = _op_def_library.OpDefLibrary()
   op_def_lib.add_op_list(op_list)
   return op_def_lib
 
diff --git a/tensorflow/python/ops/array_ops.py b/tensorflow/python/ops/array_ops.py
index e8c7ddcd49b..b83693303ac 100644
--- a/tensorflow/python/ops/array_ops.py
+++ b/tensorflow/python/ops/array_ops.py
@@ -105,6 +105,7 @@ import sys
 import numpy as np
 import six
 
+from tensorflow.python.framework import common_shapes
 from tensorflow.python.framework import constant_op
 from tensorflow.python.framework import dtypes
 from tensorflow.python.framework import ops
diff --git a/tensorflow/python/ops/sdca_ops.py b/tensorflow/python/ops/sdca_ops.py
index 84a207336fe..3876bc96421 100644
--- a/tensorflow/python/ops/sdca_ops.py
+++ b/tensorflow/python/ops/sdca_ops.py
@@ -27,16 +27,18 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
-import numpy as np
-
-from tensorflow.python import pywrap_tensorflow
 from tensorflow.python.framework import ops
+
 # go/tf-wildcard-import
 # pylint: disable=wildcard-import
 from tensorflow.python.ops.gen_sdca_ops import *
 # pylint: enable=wildcard-import
 
-# pylint: disable=anomalous-backslash-in-string,protected-access
+from tensorflow.python.util.all_util import remove_undocumented
+
 ops.NotDifferentiable("SdcaFprint")
 ops.NotDifferentiable("SdcaOptimizer")
 ops.NotDifferentiable("SdcaShrinkL1")
+
+
+remove_undocumented(__name__)
diff --git a/tensorflow/python/platform/test.py b/tensorflow/python/platform/test.py
index b6b06f9eb91..0563b370ea0 100644
--- a/tensorflow/python/platform/test.py
+++ b/tensorflow/python/platform/test.py
@@ -64,18 +64,19 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
+# pylint: disable=g-bad-import-order
 from tensorflow.python.client import device_lib as _device_lib
 from tensorflow.python.framework import test_util as _test_util
 from tensorflow.python.platform import googletest as _googletest
 from tensorflow.python.util.all_util import remove_undocumented
 
 # pylint: disable=unused-import
-from tensorflow.python.framework.test_util import TensorFlowTestCase as TestCase
 from tensorflow.python.framework.test_util import assert_equal_graph_def
+from tensorflow.python.framework.test_util import TensorFlowTestCase as TestCase
 
 from tensorflow.python.ops.gradient_checker import compute_gradient_error
 from tensorflow.python.ops.gradient_checker import compute_gradient
-# pylint: enable=unused-import
+# pylint: enable=unused-import,g-bad-import-order
 
 import sys
 if sys.version_info.major == 2:
diff --git a/tensorflow/python/user_ops/user_ops.py b/tensorflow/python/user_ops/user_ops.py
index fce89ec91bd..17dbab706c9 100644
--- a/tensorflow/python/user_ops/user_ops.py
+++ b/tensorflow/python/user_ops/user_ops.py
@@ -19,10 +19,12 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
-from tensorflow.python.ops import gen_user_ops
-from tensorflow.python.ops.gen_user_ops import *
+from tensorflow.python.ops import gen_user_ops as _gen_user_ops
+
+# go/tf-wildcard-import
+from tensorflow.python.ops.gen_user_ops import *  # pylint: disable=wildcard-import
 
 
 def my_fact():
   """Example of overriding the generated code for an Op."""
-  return gen_user_ops._fact()
+  return _gen_user_ops._fact()  # pylint: disable=protected-access
diff --git a/tensorflow/python/util/all_util.py b/tensorflow/python/util/all_util.py
index 00771573c4c..08f33657510 100644
--- a/tensorflow/python/util/all_util.py
+++ b/tensorflow/python/util/all_util.py
@@ -83,8 +83,7 @@ def reveal_undocumented(symbol_name, target_module=None):
 
 def remove_undocumented(module_name, allowed_exception_list=None,
                         doc_string_modules=None):
-  """Removes symbols in a module that are not referenced by a docstring that
-  contributes to documentation.
+  """Removes symbols in a module that are not referenced by a docstring.
 
   Args:
     module_name: the name of the module (usually `__name__`).
@@ -100,7 +99,7 @@ def remove_undocumented(module_name, allowed_exception_list=None,
   """
   current_symbols = set(dir(_sys.modules[module_name]))
   should_have = make_all(module_name, doc_string_modules)
-  should_have += allowed_exception_list
+  should_have += allowed_exception_list or []
   extra_symbols = current_symbols - set(should_have)
   target_module = _sys.modules[module_name]
   for extra_symbol in extra_symbols:
diff --git a/tensorflow/tools/common/BUILD b/tensorflow/tools/common/BUILD
index f1d43134b85..96ae9583d73 100644
--- a/tensorflow/tools/common/BUILD
+++ b/tensorflow/tools/common/BUILD
@@ -9,6 +9,22 @@ package(
     default_visibility = ["//tensorflow:__subpackages__"],
 )
 
+py_library(
+    name = "public_api",
+    srcs = ["public_api.py"],
+    srcs_version = "PY2AND3",
+)
+
+py_test(
+    name = "public_api_test",
+    srcs = ["public_api_test.py"],
+    srcs_version = "PY2AND3",
+    deps = [
+        ":public_api",
+        "//tensorflow/python:platform_test",
+    ],
+)
+
 py_library(
     name = "traverse",
     srcs = ["traverse.py"],
diff --git a/tensorflow/tools/common/public_api.py b/tensorflow/tools/common/public_api.py
new file mode 100644
index 00000000000..5d70cb7b767
--- /dev/null
+++ b/tensorflow/tools/common/public_api.py
@@ -0,0 +1,78 @@
+# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Visitor restricting traversal to only the public tensorflow API."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import inspect
+
+
+class PublicAPIVisitor(object):
+  """Visitor to use with `traverse` to visit exactly the public TF API."""
+
+  def __init__(self, visitor):
+    """Constructor.
+
+    `visitor` should be a callable suitable as a visitor for `traverse`. It will
+    be called only for members of the public TensorFlow API.
+
+    Args:
+      visitor: A visitor to call for the public API.
+    """
+    self._visitor = visitor
+
+  # Modules/classes we do not want to descend into if we hit them. Usually,
+  # sytem modules exposed through platforms for compatibility reasons.
+  # Each entry maps a module path to a name to ignore in traversal.
+  _do_not_descend_map = {
+      # TODO(drpng): This can be removed once sealed off.
+      '': ['platform', 'pywrap_tensorflow'],
+
+      # Some implementations have this internal module that we shouldn't expose.
+      'flags': ['cpp_flags'],
+
+      # Everything below here is legitimate.
+      'app': 'flags',  # It'll stay, but it's not officially part of the API
+      'test': ['mock'],  # Imported for compatibility between py2/3.
+  }
+
+  def _isprivate(self, name):
+    """Return whether a name is private."""
+    return name.startswith('_')
+
+  def _do_not_descend(self, path, name):
+    """Safely queries if a specific fully qualified name should be excluded."""
+    return (path in self._do_not_descend_map and
+            name in self._do_not_descend_map[path])
+
+  def __call__(self, path, parent, children):
+    """Visitor interface, see `traverse` for details."""
+    if inspect.ismodule(parent) and len(path.split('.')) > 10:
+      raise RuntimeError('Modules nested too deep:\n%s\n\nThis is likely a '
+                         'problem with an accidental public import.' % path)
+
+    # Remove things that are not visible.
+    for name, child in list(children):
+      if self._isprivate(name):
+        children.remove((name, child))
+
+    self._visitor(path, parent, children)
+
+    # Remove things that are visible, but which should not be descended into.
+    for name, child in list(children):
+      if self._do_not_descend(path, name):
+        children.remove((name, child))
diff --git a/tensorflow/tools/common/public_api_test.py b/tensorflow/tools/common/public_api_test.py
new file mode 100644
index 00000000000..93a3bcc2740
--- /dev/null
+++ b/tensorflow/tools/common/public_api_test.py
@@ -0,0 +1,68 @@
+# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Tests for tensorflow.tools.common.public_api."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorflow.python.platform import googletest
+from tensorflow.tools.common import public_api
+
+
+class PublicApiTest(googletest.TestCase):
+
+  class TestVisitor(object):
+
+    def __init__(self):
+      self.symbols = set()
+      self.last_parent = None
+      self.last_children = None
+
+    def __call__(self, path, parent, children):
+      self.symbols.add(path)
+      self.last_parent = parent
+      self.last_children = list(children)  # Make a copy to preserve state.
+
+  def test_call_forward(self):
+    visitor = self.TestVisitor()
+    children = [('name1', 'thing1'), ('name2', 'thing2')]
+    public_api.PublicAPIVisitor(visitor)('test', 'dummy', children)
+    self.assertEqual(set(['test']), visitor.symbols)
+    self.assertEqual('dummy', visitor.last_parent)
+    self.assertEqual([('name1', 'thing1'), ('name2', 'thing2')],
+                     visitor.last_children)
+
+  def test_private_child_removal(self):
+    visitor = self.TestVisitor()
+    children = [('name1', 'thing1'), ('_name2', 'thing2')]
+    public_api.PublicAPIVisitor(visitor)('test', 'dummy', children)
+    # Make sure the private symbols are removed before the visitor is called.
+    self.assertEqual([('name1', 'thing1')], visitor.last_children)
+    self.assertEqual([('name1', 'thing1')], children)
+
+  def test_no_descent_child_removal(self):
+    visitor = self.TestVisitor()
+    children = [('name1', 'thing1'), ('mock', 'thing2')]
+    public_api.PublicAPIVisitor(visitor)('test', 'dummy', children)
+    # Make sure not-to-be-descended-into symbols are removed after the visitor
+    # is called.
+    self.assertEqual([('name1', 'thing1'), ('mock', 'thing2')],
+                     visitor.last_children)
+    self.assertEqual([('name1', 'thing1')], children)
+
+
+if __name__ == '__main__':
+  googletest.main()