Initial Python3 support

Notable Changes:
  -Convert all str types to byte types at cython layer (ascii encoding)
  -Use six for packages that have different names in Python2/Python3
  -By default, unit tests are compiled/run in Python2.7 and Python3.4
  -Ensure MACOSX_BUILD_TARGET is at least 10.7

9 files changed, 48 insertions, 39 deletions

diff --git a/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py b/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
index 22d4b019c7..09ebdeff33 100644
--- a/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
+++ b/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
@@ -164,15 +164,15 @@ class EchoTest(unittest.TestCase):
     self.assertIsNotNone(service_accepted)
     self.assertIs(service_accepted.kind, _low.Event.Kind.SERVICE_ACCEPTED)
     self.assertIs(service_accepted.tag, service_tag)
-    self.assertEqual(method, service_accepted.service_acceptance.method)
-    self.assertEqual(self.host, service_accepted.service_acceptance.host)
+    self.assertEqual(method.encode(), service_accepted.service_acceptance.method)
+    self.assertEqual(self.host.encode(), service_accepted.service_acceptance.host)
     self.assertIsNotNone(service_accepted.service_acceptance.call)
     metadata = dict(service_accepted.metadata)
-    self.assertIn(client_metadata_key, metadata)
-    self.assertEqual(client_metadata_value, metadata[client_metadata_key])
-    self.assertIn(client_binary_metadata_key, metadata)
+    self.assertIn(client_metadata_key.encode(), metadata)
+    self.assertEqual(client_metadata_value.encode(), metadata[client_metadata_key.encode()])
+    self.assertIn(client_binary_metadata_key.encode(), metadata)
     self.assertEqual(client_binary_metadata_value,
-                     metadata[client_binary_metadata_key])
+                     metadata[client_binary_metadata_key.encode()])
     server_call = service_accepted.service_acceptance.call
     server_call.accept(self.server_completion_queue, finish_tag)
     server_call.add_metadata(server_leading_metadata_key,
@@ -186,12 +186,12 @@ class EchoTest(unittest.TestCase):
     self.assertEqual(_low.Event.Kind.METADATA_ACCEPTED, metadata_accepted.kind)
     self.assertEqual(metadata_tag, metadata_accepted.tag)
     metadata = dict(metadata_accepted.metadata)
-    self.assertIn(server_leading_metadata_key, metadata)
-    self.assertEqual(server_leading_metadata_value,
-                     metadata[server_leading_metadata_key])
-    self.assertIn(server_leading_binary_metadata_key, metadata)
+    self.assertIn(server_leading_metadata_key.encode(), metadata)
+    self.assertEqual(server_leading_metadata_value.encode(),
+                     metadata[server_leading_metadata_key.encode()])
+    self.assertIn(server_leading_binary_metadata_key.encode(), metadata)
     self.assertEqual(server_leading_binary_metadata_value,
-                     metadata[server_leading_binary_metadata_key])
+                     metadata[server_leading_binary_metadata_key.encode()])
 
     for datum in test_data:
       client_call.write(datum, write_tag, _low.WriteFlags.WRITE_NO_COMPRESS)
@@ -277,17 +277,17 @@ class EchoTest(unittest.TestCase):
     self.assertIsNone(read_accepted.bytes)
     self.assertEqual(_low.Event.Kind.FINISH, finish_accepted.kind)
     self.assertEqual(finish_tag, finish_accepted.tag)
-    self.assertEqual(_low.Status(_low.Code.OK, details), finish_accepted.status)
+    self.assertEqual(_low.Status(_low.Code.OK, details.encode()), finish_accepted.status)
     metadata = dict(finish_accepted.metadata)
-    self.assertIn(server_trailing_metadata_key, metadata)
-    self.assertEqual(server_trailing_metadata_value,
-                     metadata[server_trailing_metadata_key])
-    self.assertIn(server_trailing_binary_metadata_key, metadata)
+    self.assertIn(server_trailing_metadata_key.encode(), metadata)
+    self.assertEqual(server_trailing_metadata_value.encode(),
+                     metadata[server_trailing_metadata_key.encode()])
+    self.assertIn(server_trailing_binary_metadata_key.encode(), metadata)
     self.assertEqual(server_trailing_binary_metadata_value,
-                     metadata[server_trailing_binary_metadata_key])
+                     metadata[server_trailing_binary_metadata_key.encode()])
     self.assertSetEqual(set(key for key, _ in finish_accepted.metadata),
-                        set((server_trailing_metadata_key,
-                             server_trailing_binary_metadata_key,)))
+                        set((server_trailing_metadata_key.encode(),
+                             server_trailing_binary_metadata_key.encode(),)))
 
     self.assertSequenceEqual(test_data, server_data)
     self.assertSequenceEqual(test_data, client_data)
@@ -302,7 +302,8 @@ class EchoTest(unittest.TestCase):
     self._perform_echo_test([_BYTE_SEQUENCE])
 
   def testManyOneByteEchoes(self):
-    self._perform_echo_test(_BYTE_SEQUENCE)
+    self._perform_echo_test(
+        [_BYTE_SEQUENCE[i:i+1] for i in range(len(_BYTE_SEQUENCE))])
 
   def testManyManyByteEchoes(self):
     self._perform_echo_test(_BYTE_SEQUENCE_SEQUENCE)
@@ -409,7 +410,7 @@ class CancellationTest(unittest.TestCase):
 
     finish_event = self.client_events.get()
     self.assertEqual(_low.Event.Kind.FINISH, finish_event.kind)
-    self.assertEqual(_low.Status(_low.Code.CANCELLED, 'Cancelled'),
+    self.assertEqual(_low.Status(_low.Code.CANCELLED, b'Cancelled'),
                                  finish_event.status)
 
     self.assertSequenceEqual(test_data, server_data)
diff --git a/src/python/grpcio/tests/unit/_adapter/_low_test.py b/src/python/grpcio/tests/unit/_adapter/_low_test.py
index ec46617996..e09a1f2564 100644
--- a/src/python/grpcio/tests/unit/_adapter/_low_test.py
+++ b/src/python/grpcio/tests/unit/_adapter/_low_test.py
@@ -148,11 +148,11 @@ class InsecureServerInsecureClient(unittest.TestCase):
     # Check that Python's user agent string is a part of the full user agent
     # string
     received_initial_metadata_dict = dict(received_initial_metadata)
-    self.assertIn('user-agent', received_initial_metadata_dict)
-    self.assertIn('Python-gRPC-{}'.format(_grpcio_metadata.__version__),
-                  received_initial_metadata_dict['user-agent'])
-    self.assertEqual(method, request_event.call_details.method)
-    self.assertEqual(host, request_event.call_details.host)
+    self.assertIn(b'user-agent', received_initial_metadata_dict)
+    self.assertIn('Python-gRPC-{}'.format(_grpcio_metadata.__version__).encode(),
+                  received_initial_metadata_dict[b'user-agent'])
+    self.assertEqual(method.encode(), request_event.call_details.method)
+    self.assertEqual(host.encode(), request_event.call_details.host)
     self.assertLess(abs(deadline - request_event.call_details.deadline),
                     deadline_tolerance)
 
@@ -198,12 +198,12 @@ class InsecureServerInsecureClient(unittest.TestCase):
             test_common.metadata_transmitted(server_initial_metadata,
                                              client_result.initial_metadata))
       elif client_result.type == _types.OpType.RECV_MESSAGE:
-        self.assertEqual(response, client_result.message)
+        self.assertEqual(response.encode(), client_result.message)
       elif client_result.type == _types.OpType.RECV_STATUS_ON_CLIENT:
         self.assertTrue(
             test_common.metadata_transmitted(server_trailing_metadata,
                                              client_result.trailing_metadata))
-        self.assertEqual(server_status_details, client_result.status.details)
+        self.assertEqual(server_status_details.encode(), client_result.status.details)
         self.assertEqual(server_status_code, client_result.status.code)
     self.assertEqual(set([
           _types.OpType.SEND_INITIAL_METADATA,
@@ -220,7 +220,7 @@ class InsecureServerInsecureClient(unittest.TestCase):
       self.assertNotIn(client_result.type, found_server_op_types)
       found_server_op_types.add(server_result.type)
       if server_result.type == _types.OpType.RECV_MESSAGE:
-        self.assertEqual(request, server_result.message)
+        self.assertEqual(request.encode(), server_result.message)
       elif server_result.type == _types.OpType.RECV_CLOSE_ON_SERVER:
         self.assertFalse(server_result.cancelled)
     self.assertEqual(set([
diff --git a/src/python/grpcio/tests/unit/_cython/cygrpc_test.py b/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
index 4039c1b99b..a006a20ce3 100644
--- a/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
+++ b/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
@@ -37,7 +37,7 @@ from tests.unit import test_common
 from tests.unit import resources
 
 
-_SSL_HOST_OVERRIDE = 'foo.test.google.fr'
+_SSL_HOST_OVERRIDE = b'foo.test.google.fr'
 _CALL_CREDENTIALS_METADATA_KEY = 'call-creds-key'
 _CALL_CREDENTIALS_METADATA_VALUE = 'call-creds-value'
 _EMPTY_FLAGS = 0
diff --git a/src/python/grpcio/tests/unit/_links/_transmission_test.py b/src/python/grpcio/tests/unit/_links/_transmission_test.py
index 888684d197..1f6edd18ca 100644
--- a/src/python/grpcio/tests/unit/_links/_transmission_test.py
+++ b/src/python/grpcio/tests/unit/_links/_transmission_test.py
@@ -153,7 +153,7 @@ class RoundTripTest(unittest.TestCase):
         invocation_mate.tickets()[-1].termination,
         links.Ticket.Termination.COMPLETION)
     self.assertIs(invocation_mate.tickets()[-1].code, test_code)
-    self.assertEqual(invocation_mate.tickets()[-1].message, test_message)
+    self.assertEqual(invocation_mate.tickets()[-1].message, test_message.encode())
 
   def _perform_scenario_test(self, scenario):
     test_operation_id = object()
diff --git a/src/python/grpcio/tests/unit/_rpc_test.py b/src/python/grpcio/tests/unit/_rpc_test.py
index 1c7a14c5d0..b33bff490c 100644
--- a/src/python/grpcio/tests/unit/_rpc_test.py
+++ b/src/python/grpcio/tests/unit/_rpc_test.py
@@ -29,6 +29,8 @@
 
 """Test of gRPC Python's application-layer API."""
 
+from __future__ import division
+
 import itertools
 import threading
 import unittest
@@ -41,9 +43,9 @@ from tests.unit.framework.common import test_constants
 from tests.unit.framework.common import test_control
 
 _SERIALIZE_REQUEST = lambda bytestring: bytestring * 2
-_DESERIALIZE_REQUEST = lambda bytestring: bytestring[len(bytestring) / 2:]
+_DESERIALIZE_REQUEST = lambda bytestring: bytestring[len(bytestring) // 2:]
 _SERIALIZE_RESPONSE = lambda bytestring: bytestring * 3
-_DESERIALIZE_RESPONSE = lambda bytestring: bytestring[:len(bytestring) / 3]
+_DESERIALIZE_RESPONSE = lambda bytestring: bytestring[:len(bytestring) // 3]
 
 _UNARY_UNARY = b'/test/UnaryUnary'
 _UNARY_STREAM = b'/test/UnaryStream'
@@ -189,7 +191,7 @@ class RPCTest(unittest.TestCase):
     self._server.add_generic_rpc_handlers((_GenericHandler(self._handler),))
     self._server.start()
 
-    self._channel = grpc.insecure_channel(b'localhost:%d' % port)
+    self._channel = grpc.insecure_channel('localhost:%d' % port)
 
   # TODO(nathaniel): Why is this necessary, and only in some development
   # environments?
diff --git a/src/python/grpcio/tests/unit/beta/_beta_features_test.py b/src/python/grpcio/tests/unit/beta/_beta_features_test.py
index bb2893a21b..3a9701b8eb 100644
--- a/src/python/grpcio/tests/unit/beta/_beta_features_test.py
+++ b/src/python/grpcio/tests/unit/beta/_beta_features_test.py
@@ -42,8 +42,8 @@ from tests.unit.framework.common import test_constants
 
 _SERVER_HOST_OVERRIDE = 'foo.test.google.fr'
 
-_PER_RPC_CREDENTIALS_METADATA_KEY = 'my-call-credentials-metadata-key'
-_PER_RPC_CREDENTIALS_METADATA_VALUE = 'my-call-credentials-metadata-value'
+_PER_RPC_CREDENTIALS_METADATA_KEY = b'my-call-credentials-metadata-key'
+_PER_RPC_CREDENTIALS_METADATA_VALUE = b'my-call-credentials-metadata-value'
 
 _GROUP = 'group'
 _UNARY_UNARY = 'unary-unary'
diff --git a/src/python/grpcio/tests/unit/beta/_not_found_test.py b/src/python/grpcio/tests/unit/beta/_not_found_test.py
index 44fcd1e13c..37b8c49120 100644
--- a/src/python/grpcio/tests/unit/beta/_not_found_test.py
+++ b/src/python/grpcio/tests/unit/beta/_not_found_test.py
@@ -61,7 +61,7 @@ class NotFoundTest(unittest.TestCase):
 
   def test_future_stream_unary_not_found(self):
     rpc_future = self._generic_stub.future_stream_unary(
-        'grupe', 'mevvod', b'def', test_constants.LONG_TIMEOUT)
+        'grupe', 'mevvod', [b'def'], test_constants.LONG_TIMEOUT)
     with self.assertRaises(face.LocalError) as exception_assertion_context:
       rpc_future.result()
     self.assertIs(
diff --git a/src/python/grpcio/tests/unit/framework/interfaces/base/test_cases.py b/src/python/grpcio/tests/unit/framework/interfaces/base/test_cases.py
index 4f8e26c9a2..5d16bf98be 100644
--- a/src/python/grpcio/tests/unit/framework/interfaces/base/test_cases.py
+++ b/src/python/grpcio/tests/unit/framework/interfaces/base/test_cases.py
@@ -29,6 +29,8 @@
 
 """Tests of the base interface of RPC Framework."""
 
+from __future__ import division
+
 import logging
 import random
 import threading
@@ -54,13 +56,13 @@ class _Serialization(test_interfaces.Serialization):
     return request + request
 
   def deserialize_request(self, serialized_request):
-    return serialized_request[:len(serialized_request) / 2]
+    return serialized_request[:len(serialized_request) // 2]
 
   def serialize_response(self, response):
     return response * 3
 
   def deserialize_response(self, serialized_response):
-    return serialized_response[2 * len(serialized_response) / 3:]
+    return serialized_response[2 * len(serialized_response) // 3:]
 
 
 def _advance(quadruples, operator, controller):
diff --git a/src/python/grpcio/tests/unit/test_common.py b/src/python/grpcio/tests/unit/test_common.py
index 7b4d20dccb..b779f65e7e 100644
--- a/src/python/grpcio/tests/unit/test_common.py
+++ b/src/python/grpcio/tests/unit/test_common.py
@@ -61,6 +61,10 @@ def metadata_transmitted(original_metadata, transmitted_metadata):
   original = collections.defaultdict(list)
   for key_value_pair in original_metadata:
     key, value = tuple(key_value_pair)
+    if not isinstance(key, bytes):
+      key = key.encode()
+    if not isinstance(value, bytes):
+      value = value.encode()
     original[key].append(value)
   transmitted = collections.defaultdict(list)
   for key_value_pair in transmitted_metadata: