--- a/testing/web-platform/tests/annotation-protocol/tools/protocol-server.py
+++ b/testing/web-platform/tests/annotation-protocol/tools/protocol-server.py
@@ -9,17 +9,17 @@
 #
 # for license information, see http://www.w3.org/Consortium/Legal/2008/04-testsuite-copyright.html
 
 from __future__ import print_function
 
 import os
 import sys
 
-here = os.path.abspath(os.path.split(__file__)[0])
+here = os.path.abspath(os.path.dirname(__file__))
 repo_root = os.path.abspath(os.path.join(here, os.pardir, os.pardir))
 
 sys.path.insert(0, os.path.join(repo_root, "tools"))
 sys.path.insert(0, os.path.join(repo_root, "tools", "six"))
 sys.path.insert(0, os.path.join(repo_root, "tools", "html5lib"))
 sys.path.insert(0, os.path.join(repo_root, "tools", "wptserve"))
 sys.path.insert(0, os.path.join(repo_root, "tools", "pywebsocket", "src"))
 sys.path.insert(0, os.path.join(repo_root, "tools", "py"))

--- a/testing/web-platform/tests/css/tools/w3ctestlib/Utils.py
+++ b/testing/web-platform/tests/css/tools/w3ctestlib/Utils.py
@@ -15,17 +15,17 @@ import os.path
 from os.path import sep, pardir
 
 def assetName(path):
   return intern(os.path.splitext(os.path.basename(path))[0].lower().encode('ascii'))
   
 def basepath(path):
   """ Returns the path part of os.path.split.
   """
-  return os.path.split(path)[0]
+  return os.path.dirname(path)
 
 def isPathInsideBase(path, base=''):
   path = os.path.normpath(path)
   if base:
     base = os.path.normpath(base)
     pathlist = path.split(os.path.sep)
     baselist = base.split(os.path.sep)
     while baselist:

--- a/testing/web-platform/tests/eventsource/resources/cors.py
+++ b/testing/web-platform/tests/eventsource/resources/cors.py
@@ -26,11 +26,11 @@ def main(request, response):
             response.headers.set(b"Content-Type", b"text/event-stream")
             rv = open(os.path.join(request.doc_root, u"eventsource", u"resources", u"cache-control.event_stream"), u"r").read()
             response.content = rv
             pipes.sub(request, response)
             return
         elif handler == b"redirect":
             return run_other(request, response, os.path.join(request.doc_root, u"common", u"redirect.py"))
         else:
-            return run_other(request, response, os.path.join(os.path.split(isomorphic_decode(__file__))[0], isomorphic_decode(handler) + u".py"))
+            return run_other(request, response, os.path.join(os.path.dirname(isomorphic_decode(__file__)), isomorphic_decode(handler) + u".py"))
     else:
         return

--- a/testing/web-platform/tests/html/tools/update_html5lib_tests.py
+++ b/testing/web-platform/tests/html/tools/update_html5lib_tests.py
@@ -32,27 +32,27 @@ pip install -e ./
 
 Then run this script again, with the virtual environment still active.
 When you are done, type "deactivate" to deactivate the virtual environment.
 """)
 
 TESTS_PATH = "html/syntax/parsing/"
 
 def get_paths():
-    script_path = os.path.split(os.path.abspath(__file__))[0]
+    script_path = os.path.dirname(os.path.abspath(__file__))
     repo_base = get_repo_base(script_path)
     tests_path = os.path.join(repo_base, TESTS_PATH)
     return script_path, tests_path
 
 def get_repo_base(path):
     while path:
         if os.path.exists(os.path.join(path, ".git")):
             return path
         else:
-            path = os.path.split(path)[0]
+            path = os.path.dirname(path)
 
 def get_expected(data):
     data = "#document\n" + data
     return data
 
 def get_hash(data, container=None):
     if container == None:
         container = ""
@@ -95,17 +95,17 @@ def make_tests(script_dir, out_dir, inpu
         path_innerHTML = write_test_file(script_dir, out_dir,
                                          innerHTML_tests, "html5lib_innerHTML_%s"%input_file_name,
                                          "html5lib_test_fragment.xml")
 
     return path_normal, path_innerHTML
 
 def write_test_file(script_dir, out_dir, tests, file_name, template_file_name):
     file_name = os.path.join(out_dir, file_name + ".html")
-    short_name = os.path.split(file_name)[1]
+    short_name = os.path.basename(file_name)
 
     with open(os.path.join(script_dir, template_file_name), "r") as f:
         template = MarkupTemplate(f)
 
     stream = template.generate(file_name=short_name, tests=tests)
 
     with open(file_name, "w") as f:
         f.write(stream.render('html', doctype='html5',
@@ -134,17 +134,17 @@ def main():
         test_iterator = itertools.chain(
             itertools.izip(itertools.repeat(False),
                            sorted(support.get_data_files("tree-construction"))),
             itertools.izip(itertools.repeat(True),
                            sorted(support.get_data_files(
                         os.path.join("tree-construction", "scripted")))))
 
     for (scripted, test_file) in test_iterator:
-        input_file_name = os.path.splitext(os.path.split(test_file)[1])[0]
+        input_file_name = os.path.splitext(os.path.basename(test_file))[0]
         if scripted:
             input_file_name = "scripted_" + input_file_name
         test_data = support.TestData(test_file)
         test_filename, inner_html_file_name = make_tests(script_dir, out_dir,
                                                          input_file_name, test_data)
         if test_filename is not None:
             test_files.append(test_filename)
         if inner_html_file_name is not None:

--- a/testing/web-platform/tests/tools/localpaths.py
+++ b/testing/web-platform/tests/tools/localpaths.py
@@ -1,12 +1,12 @@
 import os
 import sys
 
-here = os.path.abspath(os.path.split(__file__)[0])
+here = os.path.abspath(os.path.dirname(__file__))
 
 sys.path.insert(0, os.path.join(here))
 sys.path.insert(0, os.path.join(here, "wptserve"))
 sys.path.insert(0, os.path.join(here, "third_party", "pywebsocket3"))
 sys.path.insert(0, os.path.join(here, "third_party", "atomicwrites"))
 sys.path.insert(0, os.path.join(here, "third_party", "attrs", "src"))
 sys.path.insert(0, os.path.join(here, "third_party", "funcsigs"))
 sys.path.insert(0, os.path.join(here, "third_party", "html5lib"))

--- a/testing/web-platform/tests/tools/wptrunner/setup.py
+++ b/testing/web-platform/tests/tools/wptrunner/setup.py
@@ -6,17 +6,17 @@ from __future__ import print_function
 
 import glob
 import os
 import sys
 import textwrap
 
 from setuptools import setup, find_packages
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 
 PACKAGE_NAME = 'wptrunner'
 PACKAGE_VERSION = '1.14'
 
 # Dependencies
 with open(os.path.join(here, "requirements.txt")) as f:
     deps = f.read().splitlines()
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py
@@ -2,17 +2,17 @@ import os
 import platform
 import socket
 from abc import ABCMeta, abstractmethod
 from copy import deepcopy
 from six import iteritems
 
 from ..wptcommandline import require_arg  # noqa: F401
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 
 
 def inherit(super_module, child_globals, product_name):
     super_wptrunner = super_module.__wptrunner__
     child_globals["__wptrunner__"] = child_wptrunner = deepcopy(super_wptrunner)
 
     child_wptrunner["product"] = product_name
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py
@@ -25,17 +25,17 @@ from ..executors import executor_kwargs 
 from ..executors.executormarionette import (MarionetteTestharnessExecutor,  # noqa: F401
                                             MarionetteRefTestExecutor,  # noqa: F401
                                             MarionettePrintRefTestExecutor,  # noqa: F401
                                             MarionetteWdspecExecutor,  # noqa: F401
                                             MarionetteCrashtestExecutor)  # noqa: F401
 from ..process import cast_env
 
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 __wptrunner__ = {"product": "firefox",
                  "check_args": "check_args",
                  "browser": "FirefoxBrowser",
                  "executor": {"crashtest": "MarionetteCrashtestExecutor",
                               "testharness": "MarionetteTestharnessExecutor",
                               "reftest": "MarionetteRefTestExecutor",
                               "print-reftest": "MarionettePrintRefTestExecutor",

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py
@@ -12,20 +12,20 @@ import time
 
 import requests
 
 from six.moves import cStringIO as StringIO
 
 from .base import Browser, ExecutorBrowser, require_arg
 from .base import get_timeout_multiplier   # noqa: F401
 from ..executors import executor_kwargs as base_executor_kwargs
-from ..executors.executorselenium import (SeleniumTestharnessExecutor,
-                                          SeleniumRefTestExecutor)
+from ..executors.executorselenium import (SeleniumTestharnessExecutor,  # noqa: F401
+                                          SeleniumRefTestExecutor)  # noqa: F401
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 # Number of seconds to wait between polling operations when detecting status of
 # Sauce Connect sub-process.
 sc_poll_period = 1
 
 
 __wptrunner__ = {"product": "sauce",
                  "check_args": "check_args",
                  "browser": "SauceBrowser",

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py
@@ -3,17 +3,17 @@ import os
 from .base import NullBrowser, ExecutorBrowser, require_arg
 from .base import get_timeout_multiplier   # noqa: F401
 from ..executors import executor_kwargs as base_executor_kwargs
 from ..executors.executorservo import (ServoCrashtestExecutor,  # noqa: F401
                                        ServoTestharnessExecutor,  # noqa: F401
                                        ServoRefTestExecutor,  # noqa: F401
                                        ServoWdspecExecutor)  # noqa: F401
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 __wptrunner__ = {
     "product": "servo",
     "check_args": "check_args",
     "browser": "ServoBrowser",
     "executor": {
         "crashtest": "ServoCrashtestExecutor",
         "testharness": "ServoTestharnessExecutor",

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py
@@ -8,17 +8,17 @@ from tools.serve.serve import make_hosts
 
 from .base import Browser, require_arg, get_free_port, browser_command, ExecutorBrowser
 from .base import get_timeout_multiplier   # noqa: F401
 from ..executors import executor_kwargs as base_executor_kwargs
 from ..executors.executorservodriver import (ServoWebDriverTestharnessExecutor,  # noqa: F401
                                              ServoWebDriverRefTestExecutor)  # noqa: F401
 from ..process import cast_env
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 __wptrunner__ = {
     "product": "servodriver",
     "check_args": "check_args",
     "browser": "ServoWebDriverBrowser",
     "executor": {
         "testharness": "ServoWebDriverTestharnessExecutor",
         "reftest": "ServoWebDriverRefTestExecutor",

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/config.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/config.py
@@ -1,30 +1,30 @@
 from six.moves.configparser import SafeConfigParser
 import os
 import sys
 from collections import OrderedDict
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 
 class ConfigDict(dict):
     def __init__(self, base_path, *args, **kwargs):
         self.base_path = base_path
         dict.__init__(self, *args, **kwargs)
 
     def get_path(self, key, default=None):
         if key not in self:
             return default
         path = self[key]
         os.path.expanduser(path)
         return os.path.abspath(os.path.join(self.base_path, path))
 
 def read(config_path):
     config_path = os.path.abspath(config_path)
-    config_root = os.path.split(config_path)[0]
+    config_root = os.path.dirname(config_path)
     parser = SafeConfigParser()
     success = parser.read(config_path)
     assert config_path in success, success
 
     subns = {"pwd": os.path.abspath(os.path.curdir)}
 
     rv = OrderedDict()
     for section in parser.sections():

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/environment.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/environment.py
@@ -6,17 +6,17 @@ import socket
 import sys
 import time
 from six import iteritems
 
 from mozlog import get_default_logger, handlers, proxy
 
 from .wptlogging import LogLevelRewriter
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 repo_root = os.path.abspath(os.path.join(here, os.pardir, os.pardir, os.pardir))
 
 sys.path.insert(0, repo_root)
 from tools import localpaths  # noqa: F401
 
 from wptserve.handlers import StringHandler
 
 serve = None

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/base.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/base.py
@@ -11,17 +11,17 @@ from abc import ABCMeta, abstractmethod
 from six import text_type
 from six.moves.http_client import HTTPConnection
 from six.moves.urllib.parse import urljoin, urlsplit, urlunsplit
 
 from ..testrunner import Stop
 from .actions import actions
 from .protocol import Protocol, BaseProtocolPart
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 
 
 def executor_kwargs(test_type, server_config, cache_manager, run_info_data,
                     **kwargs):
     timeout_multiplier = kwargs["timeout_multiplier"]
     if timeout_multiplier is None:
         timeout_multiplier = 1
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorchrome.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorchrome.py
@@ -3,17 +3,17 @@ import traceback
 
 from six.moves.urllib.parse import urljoin
 
 from .base import WdspecProtocol, WdspecExecutor, get_pages
 from .executorwebdriver import WebDriverProtocol, WebDriverRefTestExecutor, WebDriverRun
 from .protocol import PrintProtocolPart
 from ..webdriver_server import ChromeDriverServer
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 
 class ChromeDriverPrintProtocolPart(PrintProtocolPart):
     def setup(self):
         self.webdriver = self.parent.webdriver
         self.runner_handle = None
 
     def load_runner(self):

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
@@ -7,17 +7,17 @@ import uuid
 
 from six import iteritems, iterkeys
 from six.moves.urllib.parse import urljoin
 
 errors = None
 marionette = None
 pytestrunner = None
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 from .base import (CallbackHandler,
                    CrashtestExecutor,
                    RefTestExecutor,
                    RefTestImplementation,
                    TestharnessExecutor,
                    TimedRunner,
                    WdspecExecutor,

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorselenium.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorselenium.py
@@ -19,17 +19,17 @@ from .protocol import (BaseProtocolPart,
                        Protocol,
                        SelectorProtocolPart,
                        ClickProtocolPart,
                        SendKeysProtocolPart,
                        ActionSequenceProtocolPart,
                        TestDriverProtocolPart)
 from ..testrunner import Stop
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 webdriver = None
 exceptions = None
 RemoteConnection = None
 Command = None
 
 
 def do_delayed_imports():

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorservodriver.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorservodriver.py
@@ -11,17 +11,17 @@ from .base import (Protocol,
                    TimedRunner,
                    strip_server)
 from ..testrunner import Stop
 from ..webdriver_server import wait_for_service
 
 webdriver = None
 ServoCommandExtensions = None
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 
 def do_delayed_imports():
     global webdriver
     import webdriver
 
     global ServoCommandExtensions
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py
@@ -26,17 +26,17 @@ from .protocol import (BaseProtocolPart,
                        GenerateTestReportProtocolPart,
                        SetPermissionProtocolPart,
                        VirtualAuthenticatorProtocolPart)
 from ..testrunner import Stop
 
 import webdriver as client
 from webdriver import error
 
-here = os.path.join(os.path.split(__file__)[0])
+here = os.path.dirname(__file__)
 
 
 class WebDriverCallbackHandler(CallbackHandler):
     unimplemented_exc = (NotImplementedError, client.UnknownCommandException)
 
 
 class WebDriverBaseProtocolPart(BaseProtocolPart):
     def setup(self):

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/font.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/font.py
@@ -1,17 +1,17 @@
 import ctypes
 import os
 import platform
 import plistlib
 
 from shutil import copy2, rmtree
 from subprocess import call, check_output
 
-HERE = os.path.split(__file__)[0]
+HERE = os.path.dirname(__file__)
 SYSTEM = platform.system().lower()
 
 
 class FontInstaller(object):
     def __init__(self, logger, font_dir=None, **fonts):
         self.logger = logger
         self.font_dir = font_dir
         self.installed_fonts = False

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/metadata.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/metadata.py
@@ -315,17 +315,17 @@ def directory_manifests(metadata_path):
 
 def write_new_expected(metadata_path, expected):
     # Serialize the data back to a file
     path = expected_path(metadata_path, expected.test_path)
     if not expected.is_empty:
         manifest_str = wptmanifest.serialize(expected.node,
                                              skip_empty_data=True)
         assert manifest_str != ""
-        dir = os.path.split(path)[0]
+        dir = os.path.dirname(path)
         if not os.path.exists(dir):
             os.makedirs(dir)
         tmp_path = path + ".tmp"
         try:
             with open(tmp_path, "wb") as f:
                 f.write(manifest_str.encode("utf8"))
             if sys.version_info >= (3, 3):
                 os.replace(tmp_path, path)

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/__init__.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/__init__.py
@@ -1,7 +1,7 @@
 import os
 import sys
 
-here = os.path.abspath(os.path.split(__file__)[0])
+here = os.path.abspath(os.path.dirname(__file__))
 sys.path.insert(0, os.path.join(here, os.pardir, os.pardir, os.pardir))
 
 import localpaths as _localpaths  # noqa: F401

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/state.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/state.py
@@ -1,12 +1,12 @@
 import os
 from six.moves import cPickle as pickle  # noqa: N813
 
-here = os.path.abspath(os.path.split(__file__)[0])
+here = os.path.abspath(os.path.dirname(__file__))
 
 class BaseState(object):
     def __new__(cls, logger):
         rv = cls.load(logger)
         if rv is not None:
             logger.debug("Existing state found")
             return rv
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py
@@ -3,17 +3,17 @@ import os
 import re
 import shutil
 import sys
 import uuid
 
 from .base import Step, StepRunner
 from .tree import Commit
 
-here = os.path.abspath(os.path.split(__file__)[0])
+here = os.path.abspath(os.path.dirname(__file__))
 
 
 def copy_wpt_tree(tree, dest, excludes=None, includes=None):
     """Copy the working copy of a Tree to a destination directory.
 
     :param tree: The Tree to copy.
     :param dest: The destination directory"""
     if os.path.exists(dest):
@@ -36,26 +36,26 @@ def copy_wpt_tree(tree, dest, excludes=N
     for tree_path in tree.paths():
         if (any(item.match(tree_path) for item in excludes) and
             not any(item.match(tree_path) for item in includes)):
             continue
 
         source_path = os.path.join(tree.root, tree_path)
         dest_path = os.path.join(dest, tree_path)
 
-        dest_dir = os.path.split(dest_path)[0]
+        dest_dir = os.path.dirname(dest_path)
         if not os.path.isdir(source_path):
             if not os.path.exists(dest_dir):
                 os.makedirs(dest_dir)
             shutil.copy2(source_path, dest_path)
 
     for source, destination in [("testharness_runner.html", ""),
                                 ("testdriver-vendor.js", "resources/")]:
         source_path = os.path.join(here, os.pardir, source)
-        dest_path = os.path.join(dest, destination, os.path.split(source)[1])
+        dest_path = os.path.join(dest, destination, os.path.basename(source))
         shutil.copy2(source_path, dest_path)
 
 
 class UpdateCheckout(Step):
     """Pull changes from upstream into the local sync tree."""
 
     provides = ["local_branch"]
 

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py
@@ -14,17 +14,17 @@ from . import testloader
 from . import wptcommandline
 from . import wptlogging
 from . import wpttest
 from mozlog import capture, handlers
 from .font import FontInstaller
 from .testrunner import ManagerGroup
 from .browsers.base import NullBrowser
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 
 logger = None
 
 """Runner for web-platform-tests
 
 The runner has several design goals:
 
 * Tests should run with no modification from upstream.

--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py
@@ -130,17 +130,17 @@ class RunInfo(dict):
         import mozinfo
 
         path = metadata_root
         dirs = set()
         while path != os.path.expanduser('~'):
             if path in dirs:
                 break
             dirs.add(str(path))
-            path = os.path.split(path)[0]
+            path = os.path.dirname(path)
 
         mozinfo.find_and_update_from_json(*dirs)
 
 
 def server_protocol(manifest_item):
     if hasattr(manifest_item, "h2") and manifest_item.h2:
         return "h2"
     if hasattr(manifest_item, "https") and manifest_item.https:

--- a/testing/web-platform/tests/tools/wptserve/tests/functional/base.py
+++ b/testing/web-platform/tests/tools/wptserve/tests/functional/base.py
@@ -16,17 +16,17 @@ import ssl
 from localpaths import repo_root
 
 wptserve = pytest.importorskip("wptserve")
 
 logging.basicConfig()
 
 wptserve.logger.set_logger(logging.getLogger())
 
-here = os.path.split(__file__)[0]
+here = os.path.dirname(__file__)
 doc_root = os.path.join(here, "docroot")
 
 
 class Request(BaseRequest):
     def __init__(self, *args, **kwargs):
         BaseRequest.__init__(self, *args, **kwargs)
         self.method = "GET"
 

--- a/testing/web-platform/tests/tools/wptserve/wptserve/handlers.py
+++ b/testing/web-platform/tests/tools/wptserve/wptserve/handlers.py
@@ -192,17 +192,17 @@ class FileHandler(object):
             response.content = data
             response = wrap_pipeline(path, request, response)
             return response
 
         except (OSError, IOError):
             raise HTTPException(404)
 
     def get_headers(self, request, path):
-        rv = (self.load_headers(request, os.path.join(os.path.split(path)[0], "__dir__")) +
+        rv = (self.load_headers(request, os.path.join(os.path.dirname(path), "__dir__")) +
               self.load_headers(request, path))
 
         if not any(key.lower() == b"content-type" for (key, _) in rv):
             rv.insert(0, (b"Content-Type", guess_content_type(path).encode("ascii")))
 
         return rv
 
     def load_headers(self, request, path):

--- a/testing/web-platform/tests/xhr/resources/auth1/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth1/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth10/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth10/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth11/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth11/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth2/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth2/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth3/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth3/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth4/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth4/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)

--- a/testing/web-platform/tests/xhr/resources/auth9/auth.py
+++ b/testing/web-platform/tests/xhr/resources/auth9/auth.py
@@ -1,12 +1,12 @@
 import imp
 import os
 
 from wptserve.utils import isomorphic_decode
 
-here = os.path.split(os.path.abspath(isomorphic_decode(__file__)))[0]
+here = os.path.dirname(os.path.abspath(isomorphic_decode(__file__)))
 
 def main(request, response):
     auth = imp.load_source(u"", os.path.join(here,
                                              u"..",
                                              u"authentication.py"))
     return auth.main(request, response)