update_payload: Port scripts to python3

Update the update_payload scripts to be compatible with
python2 and python3. Python2 compatibility is needed since
the repo is shared with Android.

BUG=chromium:1011631

TEST=Executed aosp/system/update_engine/scripts/run_unittests and
cros_generate_update_payload

Cq-Depend: chromium:1904837, chromium:1911499
Change-Id: Ie450b80b5f7550051b38d320173ccc0c915f65e7
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/1904310
Commit-Queue: Andrew Lassalle <andrewlassalle@chromium.org>
Tested-by: Andrew Lassalle <andrewlassalle@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Auto-Submit: Andrew Lassalle <andrewlassalle@chromium.org>

1 files changed, 127 insertions, 82 deletions

diff --git a/scripts/update_payload/checker_unittest.py b/scripts/update_payload/checker_unittest.py
index 48816539..993b785c 100755
--- a/scripts/update_payload/checker_unittest.py
+++ b/scripts/update_payload/checker_unittest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python
 #
 # Copyright (C) 2013 The Android Open Source Project
 #
@@ -17,30 +17,33 @@
 
 """Unit testing checker.py."""
 
-from __future__ import print_function
+# Disable check for function names to avoid errors based on old code
+# pylint: disable-msg=invalid-name
+
+from __future__ import absolute_import
 
 import array
 import collections
-import cStringIO
 import hashlib
+import io
 import itertools
 import os
 import unittest
 
-# pylint cannot find mox.
-# pylint: disable=F0401
-import mox
+from six.moves import zip
+
+import mock  # pylint: disable=import-error
 
 from update_payload import checker
 from update_payload import common
 from update_payload import test_utils
 from update_payload import update_metadata_pb2
 from update_payload.error import PayloadError
-from update_payload.payload import Payload # Avoid name conflicts later.
+from update_payload.payload import Payload  # Avoid name conflicts later.
 
 
 def _OpTypeByName(op_name):
-  """Returns the type of an operation from itsname."""
+  """Returns the type of an operation from its name."""
   op_name_to_type = {
       'REPLACE': common.OpType.REPLACE,
       'REPLACE_BZ': common.OpType.REPLACE_BZ,
@@ -63,7 +66,7 @@ def _GetPayloadChecker(payload_gen_write_to_file_func, payload_gen_dargs=None,
   if checker_init_dargs is None:
     checker_init_dargs = {}
 
-  payload_file = cStringIO.StringIO()
+  payload_file = io.BytesIO()
   payload_gen_write_to_file_func(payload_file, **payload_gen_dargs)
   payload_file.seek(0)
   payload = Payload(payload_file)
@@ -73,7 +76,7 @@ def _GetPayloadChecker(payload_gen_write_to_file_func, payload_gen_dargs=None,
 
 def _GetPayloadCheckerWithData(payload_gen):
   """Returns a payload checker from a given payload generator."""
-  payload_file = cStringIO.StringIO()
+  payload_file = io.BytesIO()
   payload_gen.WriteToFile(payload_file)
   payload_file.seek(0)
   payload = Payload(payload_file)
@@ -87,7 +90,7 @@ def _GetPayloadCheckerWithData(payload_gen):
 # pylint: disable=W0212
 # Don't bark about missing members of classes you cannot import.
 # pylint: disable=E1101
-class PayloadCheckerTest(mox.MoxTestBase):
+class PayloadCheckerTest(unittest.TestCase):
   """Tests the PayloadChecker class.
 
   In addition to ordinary testFoo() methods, which are automatically invoked by
@@ -100,11 +103,42 @@ class PayloadCheckerTest(mox.MoxTestBase):
   all such tests is done in AddAllParametricTests().
   """
 
+  def setUp(self):
+    """setUp function for unittest testcase"""
+    self.mock_checks = []
+
+  def tearDown(self):
+    """tearDown function for unittest testcase"""
+    # Verify that all mock functions were called.
+    for check in self.mock_checks:
+      check.mock_fn.assert_called_once_with(*check.exp_args, **check.exp_kwargs)
+
+  class MockChecksAtTearDown(object):
+    """Mock data storage.
+
+    This class stores the mock functions and its arguments to be checked at a
+    later point.
+    """
+    def __init__(self, mock_fn, *args, **kwargs):
+      self.mock_fn = mock_fn
+      self.exp_args = args
+      self.exp_kwargs = kwargs
+
+  def addPostCheckForMockFunction(self, mock_fn, *args, **kwargs):
+    """Store a mock function and its arguments to self.mock_checks
+
+    Args:
+      mock_fn: mock function object
+      args: expected positional arguments for the mock_fn
+      kwargs: expected named arguments for the mock_fn
+    """
+    self.mock_checks.append(self.MockChecksAtTearDown(mock_fn, *args, **kwargs))
+
   def MockPayload(self):
     """Create a mock payload object, complete with a mock manifest."""
-    payload = self.mox.CreateMock(Payload)
+    payload = mock.create_autospec(Payload)
     payload.is_init = True
-    payload.manifest = self.mox.CreateMock(
+    payload.manifest = mock.create_autospec(
         update_metadata_pb2.DeltaArchiveManifest)
     return payload
 
@@ -173,19 +207,20 @@ class PayloadCheckerTest(mox.MoxTestBase):
     subreport = 'fake subreport'
 
     # Create a mock message.
-    msg = self.mox.CreateMock(update_metadata_pb2._message.Message)
-    msg.HasField(name).AndReturn(is_present)
+    msg = mock.create_autospec(update_metadata_pb2._message.Message)
+    self.addPostCheckForMockFunction(msg.HasField, name)
+    msg.HasField.return_value = is_present
     setattr(msg, name, val)
-
     # Create a mock report.
-    report = self.mox.CreateMock(checker._PayloadReport)
+    report = mock.create_autospec(checker._PayloadReport)
     if is_present:
       if is_submsg:
-        report.AddSubReport(name).AndReturn(subreport)
+        self.addPostCheckForMockFunction(report.AddSubReport, name)
+        report.AddSubReport.return_value = subreport
       else:
-        report.AddField(name, convert(val), linebreak=linebreak, indent=indent)
+        self.addPostCheckForMockFunction(report.AddField, name, convert(val),
+                                         linebreak=linebreak, indent=indent)
 
-    self.mox.ReplayAll()
     return (msg, report, subreport, name, val)
 
   def DoAddElemTest(self, is_present, is_mandatory, is_submsg, convert,
@@ -211,9 +246,9 @@ class PayloadCheckerTest(mox.MoxTestBase):
     else:
       ret_val, ret_subreport = checker.PayloadChecker._CheckElem(*args,
                                                                  **kwargs)
-      self.assertEquals(val if is_present else None, ret_val)
-      self.assertEquals(subreport if is_present and is_submsg else None,
-                        ret_subreport)
+      self.assertEqual(val if is_present else None, ret_val)
+      self.assertEqual(subreport if is_present and is_submsg else None,
+                       ret_subreport)
 
   def DoAddFieldTest(self, is_mandatory, is_present, convert, linebreak,
                      indent):
@@ -243,7 +278,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
       self.assertRaises(PayloadError, tested_func, *args, **kwargs)
     else:
       ret_val = tested_func(*args, **kwargs)
-      self.assertEquals(val if is_present else None, ret_val)
+      self.assertEqual(val if is_present else None, ret_val)
 
   def DoAddSubMsgTest(self, is_mandatory, is_present):
     """Parametrized testing of _Check{Mandatory,Optional}SubMsg().
@@ -267,8 +302,8 @@ class PayloadCheckerTest(mox.MoxTestBase):
       self.assertRaises(PayloadError, tested_func, *args)
     else:
       ret_val, ret_subreport = tested_func(*args)
-      self.assertEquals(val if is_present else None, ret_val)
-      self.assertEquals(subreport if is_present else None, ret_subreport)
+      self.assertEqual(val if is_present else None, ret_val)
+      self.assertEqual(subreport if is_present else None, ret_subreport)
 
   def testCheckPresentIff(self):
     """Tests _CheckPresentIff()."""
@@ -294,15 +329,14 @@ class PayloadCheckerTest(mox.MoxTestBase):
       returned_signed_hash: The signed hash data retuned by openssl.
       expected_signed_hash: The signed hash data to compare against.
     """
-    try:
-      # Stub out the subprocess invocation.
-      self.mox.StubOutWithMock(checker.PayloadChecker, '_Run')
+    # Stub out the subprocess invocation.
+    with mock.patch.object(checker.PayloadChecker, '_Run') \
+         as mock_payload_checker:
       if expect_subprocess_call:
-        checker.PayloadChecker._Run(
-            mox.IsA(list), send_data=sig_data).AndReturn(
-                (sig_asn1_header + returned_signed_hash, None))
+        mock_payload_checker([], send_data=sig_data)
+        mock_payload_checker.return_value = (
+            sig_asn1_header + returned_signed_hash, None)
 
-      self.mox.ReplayAll()
       if expect_pass:
         self.assertIsNone(checker.PayloadChecker._CheckSha256Signature(
             sig_data, 'foo', expected_signed_hash, 'bar'))
@@ -310,13 +344,11 @@ class PayloadCheckerTest(mox.MoxTestBase):
         self.assertRaises(PayloadError,
                           checker.PayloadChecker._CheckSha256Signature,
                           sig_data, 'foo', expected_signed_hash, 'bar')
-    finally:
-      self.mox.UnsetStubs()
 
   def testCheckSha256Signature_Pass(self):
     """Tests _CheckSha256Signature(); pass case."""
     sig_data = 'fake-signature'.ljust(256)
-    signed_hash = hashlib.sha256('fake-data').digest()
+    signed_hash = hashlib.sha256(b'fake-data').digest()
     self.DoCheckSha256SignatureTest(True, True, sig_data,
                                     common.SIG_ASN1_HEADER, signed_hash,
                                     signed_hash)
@@ -324,7 +356,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
   def testCheckSha256Signature_FailBadSignature(self):
     """Tests _CheckSha256Signature(); fails due to malformed signature."""
     sig_data = 'fake-signature'  # Malformed (not 256 bytes in length).
-    signed_hash = hashlib.sha256('fake-data').digest()
+    signed_hash = hashlib.sha256(b'fake-data').digest()
     self.DoCheckSha256SignatureTest(False, False, sig_data,
                                     common.SIG_ASN1_HEADER, signed_hash,
                                     signed_hash)
@@ -332,7 +364,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
   def testCheckSha256Signature_FailBadOutputLength(self):
     """Tests _CheckSha256Signature(); fails due to unexpected output length."""
     sig_data = 'fake-signature'.ljust(256)
-    signed_hash = 'fake-hash'  # Malformed (not 32 bytes in length).
+    signed_hash = b'fake-hash'  # Malformed (not 32 bytes in length).
     self.DoCheckSha256SignatureTest(False, True, sig_data,
                                     common.SIG_ASN1_HEADER, signed_hash,
                                     signed_hash)
@@ -340,16 +372,16 @@ class PayloadCheckerTest(mox.MoxTestBase):
   def testCheckSha256Signature_FailBadAsnHeader(self):
     """Tests _CheckSha256Signature(); fails due to bad ASN1 header."""
     sig_data = 'fake-signature'.ljust(256)
-    signed_hash = hashlib.sha256('fake-data').digest()
-    bad_asn1_header = 'bad-asn-header'.ljust(len(common.SIG_ASN1_HEADER))
+    signed_hash = hashlib.sha256(b'fake-data').digest()
+    bad_asn1_header = b'bad-asn-header'.ljust(len(common.SIG_ASN1_HEADER))
     self.DoCheckSha256SignatureTest(False, True, sig_data, bad_asn1_header,
                                     signed_hash, signed_hash)
 
   def testCheckSha256Signature_FailBadHash(self):
     """Tests _CheckSha256Signature(); fails due to bad hash returned."""
     sig_data = 'fake-signature'.ljust(256)
-    expected_signed_hash = hashlib.sha256('fake-data').digest()
-    returned_signed_hash = hashlib.sha256('bad-fake-data').digest()
+    expected_signed_hash = hashlib.sha256(b'fake-data').digest()
+    returned_signed_hash = hashlib.sha256(b'bad-fake-data').digest()
     self.DoCheckSha256SignatureTest(False, True, sig_data,
                                     common.SIG_ASN1_HEADER,
                                     expected_signed_hash, returned_signed_hash)
@@ -455,23 +487,23 @@ class PayloadCheckerTest(mox.MoxTestBase):
     # Add old kernel/rootfs partition info, as required.
     if fail_mismatched_oki_ori or fail_old_kernel_fs_size or fail_bad_oki:
       oki_hash = (None if fail_bad_oki
-                  else hashlib.sha256('fake-oki-content').digest())
+                  else hashlib.sha256(b'fake-oki-content').digest())
       payload_gen.SetPartInfo(common.KERNEL, False, old_kernel_fs_size,
                               oki_hash)
     if not fail_mismatched_oki_ori and (fail_old_rootfs_fs_size or
                                         fail_bad_ori):
       ori_hash = (None if fail_bad_ori
-                  else hashlib.sha256('fake-ori-content').digest())
+                  else hashlib.sha256(b'fake-ori-content').digest())
       payload_gen.SetPartInfo(common.ROOTFS, False, old_rootfs_fs_size,
                               ori_hash)
 
     # Add new kernel/rootfs partition info.
     payload_gen.SetPartInfo(
         common.KERNEL, True, new_kernel_fs_size,
-        None if fail_bad_nki else hashlib.sha256('fake-nki-content').digest())
+        None if fail_bad_nki else hashlib.sha256(b'fake-nki-content').digest())
     payload_gen.SetPartInfo(
         common.ROOTFS, True, new_rootfs_fs_size,
-        None if fail_bad_nri else hashlib.sha256('fake-nri-content').digest())
+        None if fail_bad_nri else hashlib.sha256(b'fake-nri-content').digest())
 
     # Set the minor version.
     payload_gen.SetMinorVersion(0)
@@ -518,7 +550,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
 
     # Passes w/ all real extents.
     extents = self.NewExtentList((0, 4), (8, 3), (1024, 16))
-    self.assertEquals(
+    self.assertEqual(
         23,
         payload_checker._CheckExtents(extents, (1024 + 16) * block_size,
                                       collections.defaultdict(int), 'foo'))
@@ -553,34 +585,34 @@ class PayloadCheckerTest(mox.MoxTestBase):
     block_size = payload_checker.block_size
     data_length = 10000
 
-    op = self.mox.CreateMock(
-        update_metadata_pb2.InstallOperation)
+    op = mock.create_autospec(update_metadata_pb2.InstallOperation)
     op.type = common.OpType.REPLACE
 
     # Pass.
     op.src_extents = []
     self.assertIsNone(
         payload_checker._CheckReplaceOperation(
-            op, data_length, (data_length + block_size - 1) / block_size,
+            op, data_length, (data_length + block_size - 1) // block_size,
             'foo'))
 
     # Fail, src extents founds.
     op.src_extents = ['bar']
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, data_length, (data_length + block_size - 1) / block_size, 'foo')
+        op, data_length, (data_length + block_size - 1) // block_size, 'foo')
 
     # Fail, missing data.
     op.src_extents = []
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, None, (data_length + block_size - 1) / block_size, 'foo')
+        op, None, (data_length + block_size - 1) // block_size, 'foo')
 
     # Fail, length / block number mismatch.
     op.src_extents = ['bar']
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, data_length, (data_length + block_size - 1) / block_size + 1, 'foo')
+        op, data_length, (data_length + block_size - 1) // block_size + 1,
+        'foo')
 
   def testCheckReplaceBzOperation(self):
     """Tests _CheckReplaceOperation() where op.type == REPLACE_BZ."""
@@ -588,7 +620,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
     block_size = payload_checker.block_size
     data_length = block_size * 3
 
-    op = self.mox.CreateMock(
+    op = mock.create_autospec(
         update_metadata_pb2.InstallOperation)
     op.type = common.OpType.REPLACE_BZ
 
@@ -596,25 +628,32 @@ class PayloadCheckerTest(mox.MoxTestBase):
     op.src_extents = []
     self.assertIsNone(
         payload_checker._CheckReplaceOperation(
-            op, data_length, (data_length + block_size - 1) / block_size + 5,
+            op, data_length, (data_length + block_size - 1) // block_size + 5,
             'foo'))
 
     # Fail, src extents founds.
     op.src_extents = ['bar']
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, data_length, (data_length + block_size - 1) / block_size + 5, 'foo')
+        op, data_length, (data_length + block_size - 1) // block_size + 5,
+        'foo')
 
     # Fail, missing data.
     op.src_extents = []
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, None, (data_length + block_size - 1) / block_size, 'foo')
+        op, None, (data_length + block_size - 1) // block_size, 'foo')
 
     # Fail, too few blocks to justify BZ.
     op.src_extents = []
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
+        op, data_length, (data_length + block_size - 1) // block_size, 'foo')
+
+    # Fail, total_dst_blocks is a floating point value.
+    op.src_extents = []
+    self.assertRaises(
+        PayloadError, payload_checker._CheckReplaceOperation,
         op, data_length, (data_length + block_size - 1) / block_size, 'foo')
 
   def testCheckReplaceXzOperation(self):
@@ -623,7 +662,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
     block_size = payload_checker.block_size
     data_length = block_size * 3
 
-    op = self.mox.CreateMock(
+    op = mock.create_autospec(
         update_metadata_pb2.InstallOperation)
     op.type = common.OpType.REPLACE_XZ
 
@@ -631,25 +670,32 @@ class PayloadCheckerTest(mox.MoxTestBase):
     op.src_extents = []
     self.assertIsNone(
         payload_checker._CheckReplaceOperation(
-            op, data_length, (data_length + block_size - 1) / block_size + 5,
+            op, data_length, (data_length + block_size - 1) // block_size + 5,
             'foo'))
 
     # Fail, src extents founds.
     op.src_extents = ['bar']
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, data_length, (data_length + block_size - 1) / block_size + 5, 'foo')
+        op, data_length, (data_length + block_size - 1) // block_size + 5,
+        'foo')
 
     # Fail, missing data.
     op.src_extents = []
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
-        op, None, (data_length + block_size - 1) / block_size, 'foo')
+        op, None, (data_length + block_size - 1) // block_size, 'foo')
 
     # Fail, too few blocks to justify XZ.
     op.src_extents = []
     self.assertRaises(
         PayloadError, payload_checker._CheckReplaceOperation,
+        op, data_length, (data_length + block_size - 1) // block_size, 'foo')
+
+    # Fail, total_dst_blocks is a floating point value.
+    op.src_extents = []
+    self.assertRaises(
+        PayloadError, payload_checker._CheckReplaceOperation,
         op, data_length, (data_length + block_size - 1) / block_size, 'foo')
 
   def testCheckAnyDiff(self):
@@ -724,9 +770,9 @@ class PayloadCheckerTest(mox.MoxTestBase):
     old_part_size = test_utils.MiB(4)
     new_part_size = test_utils.MiB(8)
     old_block_counters = array.array(
-        'B', [0] * ((old_part_size + block_size - 1) / block_size))
+        'B', [0] * ((old_part_size + block_size - 1) // block_size))
     new_block_counters = array.array(
-        'B', [0] * ((new_part_size + block_size - 1) / block_size))
+        'B', [0] * ((new_part_size + block_size - 1) // block_size))
     prev_data_offset = 1876
     blob_hash_counts = collections.defaultdict(int)
 
@@ -769,16 +815,14 @@ class PayloadCheckerTest(mox.MoxTestBase):
       fake_data = 'fake-data'.ljust(op.data_length)
       if not allow_unhashed and not fail_data_hash:
         # Create a valid data blob hash.
-        op.data_sha256_hash = hashlib.sha256(fake_data).digest()
-        payload.ReadDataBlob(op.data_offset, op.data_length).AndReturn(
-            fake_data)
+        op.data_sha256_hash = hashlib.sha256(fake_data.encode('utf-8')).digest()
+        payload.ReadDataBlob.return_value = fake_data.encode('utf-8')
 
       elif fail_data_hash:
         # Create an invalid data blob hash.
         op.data_sha256_hash = hashlib.sha256(
-            fake_data.replace(' ', '-')).digest()
-        payload.ReadDataBlob(op.data_offset, op.data_length).AndReturn(
-            fake_data)
+            fake_data.replace(' ', '-').encode('utf-8')).digest()
+        payload.ReadDataBlob.return_value = fake_data.encode('utf-8')
 
     total_dst_blocks = 0
     if not fail_missing_dst_extents:
@@ -807,7 +851,6 @@ class PayloadCheckerTest(mox.MoxTestBase):
             payload_checker.minor_version <= 3):
         op.dst_length = total_dst_blocks * block_size
 
-    self.mox.ReplayAll()
     should_fail = (fail_src_extents or fail_dst_extents or
                    fail_mismatched_data_offset_length or
                    fail_missing_dst_extents or fail_src_length or
@@ -857,7 +900,8 @@ class PayloadCheckerTest(mox.MoxTestBase):
       rootfs_data_length -= block_size
 
     payload_gen.AddOperation(common.ROOTFS, rootfs_op_type,
-                             dst_extents=[(0, rootfs_data_length / block_size)],
+                             dst_extents=
+                             [(0, rootfs_data_length // block_size)],
                              data_offset=0,
                              data_length=rootfs_data_length)
 
@@ -889,13 +933,13 @@ class PayloadCheckerTest(mox.MoxTestBase):
     rootfs_part_size = test_utils.MiB(2)
     kernel_part_size = test_utils.KiB(16)
     payload_gen.SetPartInfo(common.ROOTFS, True, rootfs_part_size,
-                            hashlib.sha256('fake-new-rootfs-content').digest())
+                            hashlib.sha256(b'fake-new-rootfs-content').digest())
     payload_gen.SetPartInfo(common.KERNEL, True, kernel_part_size,
-                            hashlib.sha256('fake-new-kernel-content').digest())
+                            hashlib.sha256(b'fake-new-kernel-content').digest())
     payload_gen.SetMinorVersion(0)
     payload_gen.AddOperationWithData(
         common.ROOTFS, common.OpType.REPLACE,
-        dst_extents=[(0, rootfs_part_size / block_size)],
+        dst_extents=[(0, rootfs_part_size // block_size)],
         data_blob=os.urandom(rootfs_part_size))
 
     do_forge_sigs_data = (fail_empty_sigs_blob or fail_sig_missing_fields or
@@ -908,7 +952,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
         if fail_sig_missing_fields:
           sig_data = None
         else:
-          sig_data = test_utils.SignSha256('fake-payload-content',
+          sig_data = test_utils.SignSha256(b'fake-payload-content',
                                            test_utils._PRIVKEY_FILE_NAME)
         sigs_gen.AddSig(5 if fail_unknown_sig_version else 1, sig_data)
 
@@ -984,9 +1028,9 @@ class PayloadCheckerTest(mox.MoxTestBase):
     kernel_filesystem_size = test_utils.KiB(16)
     rootfs_filesystem_size = test_utils.MiB(2)
     payload_gen.SetPartInfo(common.ROOTFS, True, rootfs_filesystem_size,
-                            hashlib.sha256('fake-new-rootfs-content').digest())
+                            hashlib.sha256(b'fake-new-rootfs-content').digest())
     payload_gen.SetPartInfo(common.KERNEL, True, kernel_filesystem_size,
-                            hashlib.sha256('fake-new-kernel-content').digest())
+                            hashlib.sha256(b'fake-new-kernel-content').digest())
     payload_gen.SetMinorVersion(0)
 
     rootfs_part_size = 0
@@ -997,7 +1041,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
       rootfs_op_size += block_size
     payload_gen.AddOperationWithData(
         common.ROOTFS, common.OpType.REPLACE,
-        dst_extents=[(0, rootfs_op_size / block_size)],
+        dst_extents=[(0, rootfs_op_size // block_size)],
         data_blob=os.urandom(rootfs_op_size))
 
     kernel_part_size = 0
@@ -1008,7 +1052,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
       kernel_op_size += block_size
     payload_gen.AddOperationWithData(
         common.KERNEL, common.OpType.REPLACE,
-        dst_extents=[(0, kernel_op_size / block_size)],
+        dst_extents=[(0, kernel_op_size // block_size)],
         data_blob=os.urandom(kernel_op_size))
 
     # Generate payload (complete w/ signature) and create the test object.
@@ -1054,6 +1098,7 @@ class PayloadCheckerTest(mox.MoxTestBase):
       else:
         self.assertIsNone(payload_checker.Run(**kwargs2))
 
+
 # This implements a generic API, hence the occasional unused args.
 # pylint: disable=W0613
 def ValidateCheckOperationTest(op_type_name, allow_unhashed,
@@ -1104,13 +1149,13 @@ def AddParametricTests(tested_method_name, arg_space, validate_func=None):
                (values) associated with them.
     validate_func: A function used for validating test argument combinations.
   """
-  for value_tuple in itertools.product(*arg_space.itervalues()):
-    run_dargs = dict(zip(arg_space.iterkeys(), value_tuple))
+  for value_tuple in itertools.product(*iter(arg_space.values())):
+    run_dargs = dict(zip(iter(arg_space.keys()), value_tuple))
     if validate_func and not validate_func(**run_dargs):
       continue
     run_method_name = 'Do%sTest' % tested_method_name
     test_method_name = 'test%s' % tested_method_name
-    for arg_key, arg_val in run_dargs.iteritems():
+    for arg_key, arg_val in run_dargs.items():
       if arg_val or isinstance(arg_val, int):
         test_method_name += '__%s=%s' % (arg_key, arg_val)
     setattr(PayloadCheckerTest, test_method_name,