diff --git a/.coveragerc b/.coveragerc
deleted file mode 100644
index f870edc..0000000
--- a/.coveragerc
+++ /dev/null
@@ -1,8 +0,0 @@
-[run]
-omit =
-    tests/*
-    wsgidav/prop_man/couch_property_manager.py
-    wsgidav/prop_man/mongo_property_manager.py
-    wsgidav/samples/*
-    wsgidav/server/run_reloading_server.py
-    wsgidav/server/server_sample.py
diff --git a/.editorconfig b/.editorconfig
index c6fcadb..4277125 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -1,21 +1,40 @@
-# EditorConfig is awesome: http://EditorConfig.org
+# EditorConfig Configurtaion file, for more details see:
+# http://EditorConfig.org
+# EditorConfig is a convention description, that could be interpreted
+# by multiple editors to enforce common coding conventions for specific
+# file types
 
-# top-most EditorConfig file
+# top-most EditorConfig file:
+# Will ignore other EditorConfig files in Home directory or upper tree level.
 root = true
 
-[*]
-
-; See https://github.com/editorconfig/editorconfig/issues/226
-;end_of_line = lf
 
+[*]  # For All Files
+# Unix-style newlines with a newline ending every file
+end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
-
-# 4 space indentation
-[*.py]
+# Set default charset
+charset = utf-8
+# Indent style default
 indent_style = space
+# Max Line Length - a hard line wrap, should be disabled
+max_line_length = off
+
+[*.{py,cfg,ini}]
+# 4 space indentation
 indent_size = 4
 
-; Tab indentation (no size specified)
-[*.js]
-indent_style = tab 
\ No newline at end of file
+[*.{yml}]
+# 2 space indentation
+indent_size = 2
+
+[*.{js}]
+# Tab indentation (no size specified)
+indent_style = tab
+
+[{Makefile,.gitmodules}]
+# Tab indentation (no size specified, but view as 4 spaces)
+indent_style = tab
+indent_size = unset
+tab_width = unset
diff --git a/.flake8 b/.flake8
deleted file mode 100644
index 5188a01..0000000
--- a/.flake8
+++ /dev/null
@@ -1,19 +0,0 @@
-[flake8]
-max-line-length = 99
-#max-line-length = 88
-
-# max-complexity = 12
-
-# Ignore some errors that may be created by Black:
-# E203 whitespace before ':'
-# E501 line too long
-# W503 line break before binary operator
-ignore = E203, E501, W503
-
-# Instead of strict E501, enable B950 for relaxed line length checking (and other bugbear warnings)
-select = B,C,E,F,Q,W,B9
-
-# Options for the flake8-quotes extension:
-inline-quotes = "
-multiline-quotes = """
-docstring-quotes = """
diff --git a/.gitignore b/.gitignore
index 368a374..9cbda6d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,8 @@ debug.log
 wsgidav.conf
 wsgidav.json
 dist
+coverage.xml
+.coverage*
 
 *.prefs
 *.project
diff --git a/.isort.cfg b/.isort.cfg
deleted file mode 100644
index 669a4ee..0000000
--- a/.isort.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-[settings]
-multi_line_output=3
-include_trailing_comma=True
-force_grid_wrap=0
-combine_as_imports=True
-line_length=88
diff --git a/.travis.yml b/.travis.yml
index e262805..2c9aee9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,21 +1,47 @@
 sudo: false
 language: python
-python:
-    - "2.7"
-#    - "3.3"  # End-of-life September 2017
-    - "3.4"
-    - "3.5"
-    - "3.6"
-    # See yaml/pyyaml#126.
-#    - "3.7-dev"  # Planned for 2018-06
 
-#sudo: required
+matrix:
+    include:
+        - python: "2.7"
+          env: TOXENV=lint-py27
+        - python: "3.6"
+          env: TOXENV=black-check,lint-py36
+        - python: "2.7"
+          env: TOXENV=py27
+        - python: "3.4"
+          env: TOXENV=py34
+        - python: "3.5"
+          env: TOXENV=py35
+        - python: "3.6"
+          env: TOXENV=py36
+        - python: "3.7"
+          env: TOXENV=py37
+        - python: "3.7-dev"
+          env: TOXENV=py37
+        - python: "3.8-dev"
+          env: TOXENV=py38
+    allow_failures:
+        - python: "3.7"
+          env: TOXENV=py37
+        - python: "3.7-dev"
+          env: TOXENV=py37
+        - python: "3.8-dev"
+          env: TOXENV=py38
+
 before_install:
     # See issue #80: litmus fails to build on travis
     # The branch 'travis-litmus' still has this enabled to investigate...
 #    - sudo apt-get install libneon27-dev
 #    - ./install_litmus.sh
+
 install:
-    pip install tox-travis
+    - travis_retry pip install -U pip setuptools
+    - travis_retry pip install -U tox coveralls coverage
+
 script:
-    tox
+    - travis_retry tox
+
+after_success:
+    - coverage combine
+    - coveralls
diff --git a/setup.cfg b/setup.cfg
index 04ee043..868cd20 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -8,3 +8,73 @@ license_file = LICENSE
 ignore =
     docs/sphinx-build
     docs/sphinx-build/*
+
+[isort]
+force_alphabetical_sort=True
+force_single_line=False
+force_to_top=True
+from_first=True
+lines_after_imports=2
+not_skip=__init__.py
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+combine_as_imports=True
+line_length=88
+
+[aliases]
+test = pytest
+
+[tool:pytest]
+addopts =
+testpaths =
+    .
+    tests
+
+[coverage:run]
+branch = True
+omit =
+    tests/*
+    wsgidav/prop_man/couch_property_manager.py
+    wsgidav/prop_man/mongo_property_manager.py
+    wsgidav/samples/*
+    wsgidav/server/run_reloading_server.py
+    wsgidav/server/server_sample.py
+
+[coverage:report]
+precision = 2
+show_missing = True
+sort = Name
+
+[coverage:html]
+directory = _build/coverage
+
+[flake8]
+max-line-length = 99
+#max-line-length = 88
+
+# max-complexity = 12
+
+# Ignore some errors that may be created by Black:
+# E203 whitespace before ':'
+# E501 line too long
+# W503 line break before binary operator
+ignore =
+    E203,
+    E501,
+    W503
+
+# Instead of strict E501, enable B950 for relaxed line length checking (and other bugbear warnings)
+select =
+    B,
+    C,
+    E,
+    F,
+    Q,
+    W,
+    B9
+
+# Options for the flake8-quotes extension:
+inline-quotes = "
+multiline-quotes = """
+docstring-quotes = """
diff --git a/setup.py b/setup.py
index 747351d..ba632da 100644
--- a/setup.py
+++ b/setup.py
@@ -1,17 +1,16 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
 
 from __future__ import print_function
+from setuptools import Command, find_packages, setup
+from setuptools.command.test import test as TestCommand
+from wsgidav._version import __version__
 
 # from datetime import datetime
 import os
 import sys
 
-from setuptools import setup, find_packages
-from setuptools import Command
-from setuptools.command.test import test as TestCommand
-
-from wsgidav._version import __version__
-
 
 version = __version__
 
diff --git a/tests/benchmarks.py b/tests/benchmarks.py
index 73cbeac..8b6d98f 100644
--- a/tests/benchmarks.py
+++ b/tests/benchmarks.py
@@ -49,6 +49,9 @@ Test cases
         file10-10-1.txt -> 1k
 """
 from __future__ import print_function
+from tests.util import Timing, WsgiDavTestServer
+from wsgidav import __version__
+from wsgidav.xml_tools import use_lxml
 
 import datetime
 import logging
@@ -57,9 +60,6 @@ import platform
 import subprocess
 import sys
 
-from tests.util import Timing, WsgiDavTestServer
-from wsgidav import __version__
-from wsgidav.xml_tools import use_lxml
 
 try:
     # WsgiDAV 2.x
diff --git a/tests/conftest.py b/tests/conftest.py
index bbbf88d..8868bd4 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,7 +1,9 @@
+# -*- coding: utf-8 -*-
+
 import os
+import pkg_resources
 import sys
 
-import pkg_resources
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
 pkg_resources.require("wsgidav")
diff --git a/tests/davclient.py b/tests/davclient.py
index 70c1bcb..41ba76c 100644
--- a/tests/davclient.py
+++ b/tests/davclient.py
@@ -26,9 +26,9 @@
 # - Use requests instead of http.client / httplib
 
 import copy
+import requests
 import sys
 
-import requests
 
 PY2 = sys.version_info < (3, 0)
 
diff --git a/tests/test_http.py b/tests/test_http.py
index 8f62507..4dfb700 100644
--- a/tests/test_http.py
+++ b/tests/test_http.py
@@ -7,11 +7,11 @@
 
     This test suite uses requests to generate HTTP requests.
 """
-import unittest
+from tests.util import WsgiDavTestServer
 
 import requests
+import unittest
 
-from tests.util import WsgiDavTestServer
 
 _test_server = None
 
diff --git a/tests/test_litmus.py b/tests/test_litmus.py
index c63d6e9..4eff8f8 100644
--- a/tests/test_litmus.py
+++ b/tests/test_litmus.py
@@ -6,11 +6,11 @@
     Run litmus against WsgiDAV server.
 """
 from __future__ import print_function
+from tests.util import WsgiDavTestServer
 
 import subprocess
 import unittest
 
-from tests.util import WsgiDavTestServer
 
 # ========================================================================
 # WsgiDAVServerTest
diff --git a/tests/test_lock_manager.py b/tests/test_lock_manager.py
index fc08a29..e31daa8 100644
--- a/tests/test_lock_manager.py
+++ b/tests/test_lock_manager.py
@@ -3,14 +3,15 @@
 # Licensed under the MIT license:
 # http://www.opensource.org/licenses/mit-license.php
 """Unit test for lock_manager.py"""
+from tempfile import gettempdir
+from time import sleep
+from wsgidav import lock_manager, lock_storage
+from wsgidav.dav_error import DAVError
+
 import os
 import sys
 import unittest
-from tempfile import gettempdir
-from time import sleep
 
-from wsgidav import lock_manager, lock_storage
-from wsgidav.dav_error import DAVError
 
 # ========================================================================
 # BasicTest
diff --git a/tests/test_property_manager.py b/tests/test_property_manager.py
index c658b94..98e455c 100644
--- a/tests/test_property_manager.py
+++ b/tests/test_property_manager.py
@@ -3,12 +3,13 @@
 # Licensed under the MIT license:
 # http://www.opensource.org/licenses/mit-license.php
 """Unit test for property_manager.py"""
+from tempfile import gettempdir
+from wsgidav.prop_man import property_manager
+
 import os
 import sys
 import unittest
-from tempfile import gettempdir
 
-from wsgidav.prop_man import property_manager
 
 # ========================================================================
 # BasicTest
diff --git a/tests/test_scripted.py b/tests/test_scripted.py
index 3e38f58..1457998 100644
--- a/tests/test_scripted.py
+++ b/tests/test_scripted.py
@@ -11,20 +11,20 @@
         http://svn.osafoundation.org/tools/davclient/trunk/src/davclient/davclient.py
 """
 from __future__ import print_function
-
-import os
-import time
-import unittest
 from tempfile import gettempdir
-from threading import Thread
-
 from tests import davclient
 from tests.util import WsgiDavTestServer
+from threading import Thread
 from wsgidav import compat
 from wsgidav.fs_dav_provider import FilesystemProvider
 from wsgidav.server.ext_wsgiutils_server import ExtServer
 from wsgidav.wsgidav_app import WsgiDAVApp
 
+import os
+import time
+import unittest
+
+
 # SERVER_ADDRESS
 # (using localhost or mixing hostnames with IPs may be very slow!)
 SERVER_ADDRESS = "http://127.0.0.1:8080"
@@ -61,7 +61,7 @@ def setUpModule():
             _test_server = WsgiDAVServerThread()
             _test_server.start()
             # let server start the loop, otherwise shutdown might lock
-            time.sleep(.1)
+            time.sleep(0.1)
     return
 
 
@@ -150,7 +150,7 @@ class WsgiDAVServerThread(Thread):
             print("WsgiDAVServerThread.shutdown()...")
             # let server process pending requests, otherwise shutdown might
             # lock
-            time.sleep(.1)
+            time.sleep(0.1)
             self.ext_server.stop_serve_forever()
             self.ext_server = None
             print("WsgiDAVServerThread.shutdown()... complete")
diff --git a/tests/test_streaming.py b/tests/test_streaming.py
index 74e891f..ccbb229 100644
--- a/tests/test_streaming.py
+++ b/tests/test_streaming.py
@@ -7,17 +7,17 @@
 Unit tests for wsgidav.stream_tools.FileLikeQueue
 """
 
+from tempfile import gettempdir
+from tests.util import Timing, write_test_file, WsgiDavTestServer
+from wsgidav import compat
+from wsgidav.dav_provider import DAVNonCollection, DAVProvider
+from wsgidav.stream_tools import FileLikeQueue
+
 import os
+import requests
 import threading
 import unittest
-from tempfile import gettempdir
 
-import requests
-
-from tests.util import Timing, WsgiDavTestServer, write_test_file
-from wsgidav import compat
-from wsgidav.stream_tools import FileLikeQueue
-from wsgidav.dav_provider import DAVNonCollection, DAVProvider
 
 # ----------------------------------------------------------------------------
 # Dummy DAVProvider implementation
diff --git a/tests/test_util.py b/tests/test_util.py
index 03f3212..7e76b30 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -4,11 +4,6 @@
 # http://www.opensource.org/licenses/mit-license.php
 """Unit tests for wsgidav.util"""
 from __future__ import print_function
-
-import logging
-import logging.handlers
-import unittest
-
 from wsgidav.compat import StringIO
 from wsgidav.util import (
     BASE_LOGGER_NAME,
@@ -22,6 +17,10 @@ from wsgidav.util import (
     shift_path,
 )
 
+import logging
+import logging.handlers
+import unittest
+
 
 class BasicTest(unittest.TestCase):
     """Test ."""
diff --git a/tests/test_wsgidav_app.py b/tests/test_wsgidav_app.py
index e318f06..a6acbf0 100644
--- a/tests/test_wsgidav_app.py
+++ b/tests/test_wsgidav_app.py
@@ -12,16 +12,16 @@
         (successor of http://pythonpaste.org/testing-applications.html)
 """
 from __future__ import print_function
+from tempfile import gettempdir
+from wsgidav import compat, util
+from wsgidav.fs_dav_provider import FilesystemProvider
+from wsgidav.wsgidav_app import WsgiDAVApp
 
 import os
 import shutil
 import sys
 import unittest
-from tempfile import gettempdir
 
-from wsgidav import compat, util
-from wsgidav.fs_dav_provider import FilesystemProvider
-from wsgidav.wsgidav_app import WsgiDAVApp
 
 try:
     import webtest
diff --git a/tests/util.py b/tests/util.py
index 6c3ac93..50432d9 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -10,16 +10,16 @@ Example:
         ... test methods
 """
 from __future__ import print_function
+from tempfile import gettempdir
+from wsgidav import compat, util
+from wsgidav.fs_dav_provider import FilesystemProvider
+from wsgidav.wsgidav_app import WsgiDAVApp
 
 import multiprocessing
 import os
 import sys
 import time
-from tempfile import gettempdir
 
-from wsgidav import compat, util
-from wsgidav.fs_dav_provider import FilesystemProvider
-from wsgidav.wsgidav_app import WsgiDAVApp
 
 # ========================================================================
 # Timing
diff --git a/tox.ini b/tox.ini
index a829f5e..fd8ec40 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,45 +1,134 @@
 [tox]
 basepython = python3.6
-#envlist = clean, py27, py34, py35, stats
-envlist = check, py27, py34, py35, py36, py37
+envlist =
+    py27,
+    py34,
+    py35,
+    py36,
+    py37,
+    black-check,
+    lint-py27,
+    lint-py36,
+    coverage,
 
 [testenv]
+usedevelop = True
+extras =
+    test
+
 passenv = LC_ALL LANG TRAVIS TRAVIS_BRANCH TRAVIS_OS_NAME TRAVIS_BUILD_ID
 
+setenv =
+  COVERAGE_FILE=.coverage.{envname}
+
 # Note: also honors .coveragerc:
 commands =
     # Run everything from /tests folder:
-    py.test -ra -v -x --cov wsgidav tests
-    # Check PEP8 style:
-    flake8 --version
-    flake8 wsgidav tests
+    python -V
+    pip list
+    pytest -ra -v -x --cov=wsgidav --cov-report=xml --html=_build/pytest/report-{envname}.html --self-contained-html {posargs}
 
 deps =
     cheroot
     defusedxml
-    flake8
-    flake8-quotes
     Jinja2
     jsmin
     PyYAML
     pytest
     pytest-cov
+    #pytest-remove-stale-bytecode
+    pytest-html
     requests
     webtest
 
+[testenv:coverage]
+skip_install = true
 
-[testenv:check]
-description = Check Black formatting compliance and add flake8-bugbear checks
-basepython = python3.6
-changedir = {toxinidir}
+deps =
+    coverage
+
+setenv =
+  COVERAGE_FILE=.coverage
+
+commands =
+    coverage erase
+    coverage combine
+    coverage html
+    coverage xml
+    coverage report --fail-under=30.0
+
+
+[testenv:isort-apply]
 skip_install = true
 deps =
-    black
-    flake8-bugbear
-commands =
-    black --check --diff wsgidav tests
-    flake8 wsgidav tests
+    isort
 
+commands =
+    isort --apply --recursive {toxinidir}/wsgidav {toxinidir}/tests setup.py {posargs}
+
+[testenv:autopep8]
+skip_install = true
+deps =
+    autopep8
+    docformatter
+
+commands =
+    autopep8 --verbose --in-place --recursive --aggressive --aggressive {toxinidir}/wsgidav {toxinidir}/tests setup.py
+    docformatter --in-place --recursive {toxinidir}/wsgidav {toxinidir}/tests setup.py
+
+[lint]
+skip_install = true
+
+deps =
+    isort
+    flake8
+    # helper to generate HTML reports:
+    flake8-html
+    # Useful flake8 plugins that are Python and Plone specific:
+    flake8-coding
+    flake8-debugger
+    flake8-deprecated
+    flake8-pytest
+    flake8-quotes
+    flake8-todo
+    flake8-isort
+    mccabe
+    # Potential flake8 plugins that should be used:  # TBD
+    #flake8-blind-except
+    #flake8-commas
+    #flake8-docstrings
+    #flake8-mypy
+    #flake8-pep3101
+    #flake8-plone-hasattr
+    #flake8-string-format
+    #flake8_strict
+    #flake8-quotes
+
+commands =
+    mkdir -p {toxinidir}/_build/flake8
+    isort --check-only --recursive {toxinidir}/wsgidav {toxinidir}/tests setup.py
+    - flake8 --format=html --htmldir={toxinidir}/_build/flake8 --doctests wsgidav tests setup.py
+    flake8 wsgidav tests setup.py --doctests
+
+whitelist_externals =
+    mkdir
+
+[testenv:lint-py27]
+basepython = python2.7
+skip_install = true
+deps =
+    {[lint]deps}
+commands = {[lint]commands}
+whitelist_externals = {[lint]whitelist_externals}
+
+[testenv:lint-py36]
+basepython = python3.6
+skip_install = true
+deps =
+    {[lint]deps}
+    flake8-bugbear
+commands = {[lint]commands}
+whitelist_externals = {[lint]whitelist_externals}
 
 [testenv:black]
 description = Reformat python code using Black
@@ -49,8 +138,17 @@ skip_install = true
 deps =
     black
 commands =
-    black wsgidav tests
+    black wsgidav tests setup.py
 
+[testenv:black-check]
+description = Check Black formatting compliance and add flake8-bugbear checks
+basepython = python3.6
+changedir = {toxinidir}
+skip_install = true
+deps =
+    black
+commands =
+    black --check --diff wsgidav tests setup.py
 
 [testenv:docs]
 description = Build Sphinx documentation (output directory: docs/sphinx-build)
diff --git a/wsgidav/__init__.py b/wsgidav/__init__.py
index 11f729b..491ed40 100644
--- a/wsgidav/__init__.py
+++ b/wsgidav/__init__.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # make version accessible as 'wsgidav.__version__'
 
 from wsgidav._version import __version__  # noqa: F401
@@ -7,6 +8,7 @@ from wsgidav._version import __version__  # noqa: F401
 # https://docs.python.org/3/howto/logging.html#configuring-logging-for-a-library
 import logging
 
+
 _base_logger = logging.getLogger(__name__)
 _base_logger.addHandler(logging.NullHandler())
 _base_logger.propagate = False
diff --git a/wsgidav/_version.py b/wsgidav/_version.py
index 252a7ee..a2f4eae 100644
--- a/wsgidav/_version.py
+++ b/wsgidav/_version.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 """
 Current WsgiDAV version number.
 
diff --git a/wsgidav/compat.py b/wsgidav/compat.py
index 62c965e..e285504 100644
--- a/wsgidav/compat.py
+++ b/wsgidav/compat.py
@@ -11,6 +11,7 @@ Inspired by six https://pythonhosted.org/six/
 
 import sys
 
+
 __docformat__ = "reStructuredText"
 
 #: True if we are running on Python 2.x
diff --git a/wsgidav/dav_error.py b/wsgidav/dav_error.py
index 9217fad..0c02b23 100644
--- a/wsgidav/dav_error.py
+++ b/wsgidav/dav_error.py
@@ -6,11 +6,12 @@
 """
 Implements a DAVError class that is used to signal WebDAV and HTTP errors.
 """
-import datetime
-
 from wsgidav import __version__, compat, xml_tools
 from wsgidav.xml_tools import etree
 
+import datetime
+
+
 # import traceback
 
 
diff --git a/wsgidav/dav_provider.py b/wsgidav/dav_provider.py
index 51d0061..95e0e96 100644
--- a/wsgidav/dav_provider.py
+++ b/wsgidav/dav_provider.py
@@ -76,26 +76,21 @@ lockManager
 
 See :doc:`reference_guide` for more information about the WsgiDAV architecture.
 """
+from wsgidav import compat, util, xml_tools
+from wsgidav.dav_error import (
+    as_DAVError,
+    DAVError,
+    HTTP_FORBIDDEN,
+    HTTP_NOT_FOUND,
+    PRECONDITION_CODE_ProtectedProperty,
+)
+from wsgidav.util import etree
+
 import os
 import sys
 import time
 import traceback
 
-from wsgidav import compat, util, xml_tools
-from wsgidav.dav_error import (
-    HTTP_FORBIDDEN,
-    HTTP_NOT_FOUND,
-    DAVError,
-    PRECONDITION_CODE_ProtectedProperty,
-    as_DAVError,
-)
-
-# Trick PyDev to do intellisense and don't produce warnings:
-from wsgidav.util import etree  # noqa
-
-if False:
-    from xml.etree import ElementTree as etree  # noqa
-
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/dc/nt_dc.py b/wsgidav/dc/nt_dc.py
index 828a63f..0a552fd 100644
--- a/wsgidav/dc/nt_dc.py
+++ b/wsgidav/dc/nt_dc.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # (c) 2009-2018 Martin Wendt and contributors; see WsgiDAV https://github.com/mar10/wsgidav
 # Original PyFileServer (c) 2005 Ho Chun Wei.
 # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
@@ -72,12 +73,12 @@ Testability and caveats
 ml
 """
 from __future__ import print_function
+from wsgidav import compat, util
 
 import win32net
 import win32netcon
 import win32security
 
-from wsgidav import compat, util
 
 __docformat__ = "reStructuredText"
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/dc/simple_dc.py b/wsgidav/dc/simple_dc.py
index 247caa6..c7f9cee 100644
--- a/wsgidav/dc/simple_dc.py
+++ b/wsgidav/dc/simple_dc.py
@@ -32,9 +32,10 @@ domaincontrollerinterface_
 .. _domaincontrollerinterface : interfaces/domaincontrollerinterface.py
 
 """
+from wsgidav import util
+
 import sys
 
-from wsgidav import util
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/debug_filter.py b/wsgidav/debug_filter.py
index 1a4b0c5..b47e988 100644
--- a/wsgidav/debug_filter.py
+++ b/wsgidav/debug_filter.py
@@ -51,13 +51,14 @@ These configuration settings are evaluated:
         debug_litmus = ["notowner_modify", "props: 16", ]
 
 """
-import sys
-import threading
-
 from wsgidav import compat, util
 from wsgidav.middleware import BaseMiddleware
 from wsgidav.util import safe_re_encode
 
+import sys
+import threading
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/default_conf.py b/wsgidav/default_conf.py
index b7895c9..c3da6db 100644
--- a/wsgidav/default_conf.py
+++ b/wsgidav/default_conf.py
@@ -14,12 +14,13 @@
 
 Default confguration.
 """
-from wsgidav.dir_browser import WsgiDavDirBrowser
 from wsgidav.debug_filter import WsgiDavDebugFilter
+from wsgidav.dir_browser import WsgiDavDirBrowser
 from wsgidav.error_printer import ErrorPrinter
 from wsgidav.http_authenticator import HTTPAuthenticator
 from wsgidav.request_resolver import RequestResolver
 
+
 __docformat__ = "reStructuredText"
 
 # Use these settings, if config file does not define them (or is totally missing)
diff --git a/wsgidav/dir_browser/_dir_browser.py b/wsgidav/dir_browser/_dir_browser.py
index 894c5ce..39ab9e5 100644
--- a/wsgidav/dir_browser/_dir_browser.py
+++ b/wsgidav/dir_browser/_dir_browser.py
@@ -6,15 +6,15 @@
 WSGI middleware that handles GET requests on collections to display directories.
 """
 from fnmatch import fnmatch
+from jinja2 import Environment, FileSystemLoader
+from wsgidav import __version__, compat, util
+from wsgidav.dav_error import DAVError, HTTP_MEDIATYPE_NOT_SUPPORTED, HTTP_OK
+from wsgidav.middleware import BaseMiddleware
+from wsgidav.util import safe_re_encode
+
 import os
 import sys
 
-from jinja2 import Environment, FileSystemLoader
-
-from wsgidav import __version__, compat, util
-from wsgidav.dav_error import HTTP_MEDIATYPE_NOT_SUPPORTED, HTTP_OK, DAVError
-from wsgidav.middleware import BaseMiddleware
-from wsgidav.util import safe_re_encode
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/error_printer.py b/wsgidav/error_printer.py
index 1f00ce5..27c4725 100644
--- a/wsgidav/error_printer.py
+++ b/wsgidav/error_printer.py
@@ -7,19 +7,20 @@
 WSGI middleware to catch application thrown DAVErrors and return proper
 responses.
 """
-import traceback
-
 from wsgidav import util
 from wsgidav.dav_error import (
+    as_DAVError,
+    DAVError,
+    get_http_status_string,
     HTTP_INTERNAL_ERROR,
     HTTP_NO_CONTENT,
     HTTP_NOT_MODIFIED,
-    DAVError,
-    as_DAVError,
-    get_http_status_string,
 )
 from wsgidav.middleware import BaseMiddleware
 
+import traceback
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/fs_dav_provider.py b/wsgidav/fs_dav_provider.py
index 3c2f444..d5aba00 100644
--- a/wsgidav/fs_dav_provider.py
+++ b/wsgidav/fs_dav_provider.py
@@ -15,14 +15,15 @@ This provider creates instances of :class:`~wsgidav.fs_dav_provider.FileResource
 and :class:`~wsgidav.fs_dav_provider.FolderResource` to represent files and
 directories respectively.
 """
+from wsgidav import compat, util
+from wsgidav.dav_error import DAVError, HTTP_FORBIDDEN
+from wsgidav.dav_provider import DAVCollection, DAVNonCollection, DAVProvider
+
 import os
 import shutil
 import stat
 import sys
 
-from wsgidav import compat, util
-from wsgidav.dav_error import HTTP_FORBIDDEN, DAVError
-from wsgidav.dav_provider import DAVCollection, DAVNonCollection, DAVProvider
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/http_authenticator.py b/wsgidav/http_authenticator.py
index 04f73b1..5ecf074 100644
--- a/wsgidav/http_authenticator.py
+++ b/wsgidav/http_authenticator.py
@@ -75,17 +75,18 @@ The environ variable here is the WSGI 'environ' dictionary. It is passed to
 all methods of the domain controller as a means for developers to pass information
 from previous middleware or server config (if required).
 """
-import inspect
-import random
-import re
-import time
 from hashlib import md5
-
 from wsgidav import compat, util
 from wsgidav.dc.simple_dc import SimpleDomainController
 from wsgidav.middleware import BaseMiddleware
 from wsgidav.util import calc_base64, calc_hexdigest, dynamic_import_class
 
+import inspect
+import random
+import re
+import time
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/interfaces/dav_provider_interface.py b/wsgidav/interfaces/dav_provider_interface.py
index eda0a26..e368cca 100644
--- a/wsgidav/interfaces/dav_provider_interface.py
+++ b/wsgidav/interfaces/dav_provider_interface.py
@@ -1,3 +1,6 @@
+# -*- coding: utf-8 -*-
+
+
 class IDAVProvider(object):
     """
     +----------------------------------------------------------------------+
diff --git a/wsgidav/interfaces/domaincontrollerinterface.py b/wsgidav/interfaces/domaincontrollerinterface.py
index 1dab7a1..2e5f7cf 100644
--- a/wsgidav/interfaces/domaincontrollerinterface.py
+++ b/wsgidav/interfaces/domaincontrollerinterface.py
@@ -1,3 +1,6 @@
+# -*- coding: utf-8 -*-
+
+
 class IDomainController(object):
     """
     +----------------------------------------------------------------------+
diff --git a/wsgidav/interfaces/lockmanagerinterface.py b/wsgidav/interfaces/lockmanagerinterface.py
index 57c063d..d92280f 100644
--- a/wsgidav/interfaces/lockmanagerinterface.py
+++ b/wsgidav/interfaces/lockmanagerinterface.py
@@ -1,3 +1,6 @@
+# -*- coding: utf-8 -*-
+
+
 class LockManagerInterface(object):
     """
     +----------------------------------------------------------------------+
diff --git a/wsgidav/interfaces/propertymanagerinterface.py b/wsgidav/interfaces/propertymanagerinterface.py
index f8158f9..a2ab08f 100644
--- a/wsgidav/interfaces/propertymanagerinterface.py
+++ b/wsgidav/interfaces/propertymanagerinterface.py
@@ -1,3 +1,6 @@
+# -*- coding: utf-8 -*-
+
+
 class PropertyManagerInterface(object):
     """
     +----------------------------------------------------------------------+
diff --git a/wsgidav/lock_manager.py b/wsgidav/lock_manager.py
index fbbfcb4..6263fd2 100644
--- a/wsgidav/lock_manager.py
+++ b/wsgidav/lock_manager.py
@@ -36,19 +36,20 @@ The lock data model is a dictionary with these fields:
         Automatically generated unique token.
 
 """
-import random
-import time
 from pprint import pformat
-
 from wsgidav import compat, util
 from wsgidav.dav_error import (
-    HTTP_LOCKED,
     DAVError,
     DAVErrorCondition,
+    HTTP_LOCKED,
     PRECONDITION_CODE_LockConflict,
 )
 from wsgidav.rw_lock import ReadWriteLock
 
+import random
+import time
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/lock_storage.py b/wsgidav/lock_storage.py
index 663cc9d..4ff7627 100644
--- a/wsgidav/lock_storage.py
+++ b/wsgidav/lock_storage.py
@@ -11,10 +11,6 @@ Two alternative lock storage classes are defined here: one in-memory
 
 See :class:`~wsgidav.lock_manager.LockManager`
 """
-import os
-import shelve
-import time
-
 from wsgidav import compat, util
 from wsgidav.lock_manager import (
     generate_lock_token,
@@ -24,6 +20,11 @@ from wsgidav.lock_manager import (
 )
 from wsgidav.rw_lock import ReadWriteLock
 
+import os
+import shelve
+import time
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/prop_man/__init__.py b/wsgidav/prop_man/__init__.py
index e69de29..40a96af 100644
--- a/wsgidav/prop_man/__init__.py
+++ b/wsgidav/prop_man/__init__.py
@@ -0,0 +1 @@
+# -*- coding: utf-8 -*-
diff --git a/wsgidav/prop_man/couch_property_manager.py b/wsgidav/prop_man/couch_property_manager.py
index 8f53cf9..18573f6 100644
--- a/wsgidav/prop_man/couch_property_manager.py
+++ b/wsgidav/prop_man/couch_property_manager.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # (c) 2009-2018 Martin Wendt and contributors; see WsgiDAV https://github.com/mar10/wsgidav
 # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
 """
@@ -22,11 +23,11 @@ Valid options are (sample shows defaults)::
 
 """
 from __future__ import print_function
-
 from uuid import uuid4
+from wsgidav import compat, util
 
 import couchdb
-from wsgidav import compat, util
+
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/prop_man/mongo_property_manager.py b/wsgidav/prop_man/mongo_property_manager.py
index d87dd8c..b3d835d 100644
--- a/wsgidav/prop_man/mongo_property_manager.py
+++ b/wsgidav/prop_man/mongo_property_manager.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # (c) 2009-2018 Martin Wendt and contributors; see WsgiDAV https://github.com/mar10/wsgidav
 # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
 """
@@ -22,9 +23,10 @@ Valid options are (sample shows defaults)::
 
 """
 from __future__ import print_function
+from wsgidav import compat, util
 
 import pymongo
-from wsgidav import compat, util
+
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/prop_man/property_manager.py b/wsgidav/prop_man/property_manager.py
index 4a2a838..edbf36d 100644
--- a/wsgidav/prop_man/property_manager.py
+++ b/wsgidav/prop_man/property_manager.py
@@ -18,11 +18,12 @@ The properties dictionaray is built like::
       }
 
 """
+from wsgidav import util
+from wsgidav.rw_lock import ReadWriteLock
+
 import os
 import shelve
 
-from wsgidav import util
-from wsgidav.rw_lock import ReadWriteLock
 
 # TODO: comment's from Ian Bicking (2005)
 # @@: Use of shelve means this is only really useful in a threaded environment.
diff --git a/wsgidav/request_resolver.py b/wsgidav/request_resolver.py
index 160a61f..2d44203 100644
--- a/wsgidav/request_resolver.py
+++ b/wsgidav/request_resolver.py
@@ -88,10 +88,11 @@ header, if present, to::
 
 """
 from wsgidav import util
-from wsgidav.dav_error import HTTP_NOT_FOUND, DAVError
+from wsgidav.dav_error import DAVError, HTTP_NOT_FOUND
 from wsgidav.middleware import BaseMiddleware
 from wsgidav.request_server import RequestServer
 
+
 __docformat__ = "reStructuredText"
 
 # NOTE (Martin Wendt, 2009-05):
diff --git a/wsgidav/request_server.py b/wsgidav/request_server.py
index b48b47e..aae706f 100644
--- a/wsgidav/request_server.py
+++ b/wsgidav/request_server.py
@@ -8,6 +8,9 @@ WSGI application that handles one single WebDAV request.
 """
 from wsgidav import compat, util, xml_tools
 from wsgidav.dav_error import (
+    as_DAVError,
+    DAVError,
+    get_http_status_string,
     HTTP_BAD_GATEWAY,
     HTTP_BAD_REQUEST,
     HTTP_CONFLICT,
@@ -24,14 +27,12 @@ from wsgidav.dav_error import (
     HTTP_OK,
     HTTP_PRECONDITION_FAILED,
     HTTP_RANGE_NOT_SATISFIABLE,
-    DAVError,
     PRECONDITION_CODE_LockTokenMismatch,
     PRECONDITION_CODE_PropfindFiniteDepth,
-    as_DAVError,
-    get_http_status_string,
 )
 from wsgidav.util import etree
 
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/rw_lock.py b/wsgidav/rw_lock.py
index e6e4fae..a0b373f 100644
--- a/wsgidav/rw_lock.py
+++ b/wsgidav/rw_lock.py
@@ -15,9 +15,10 @@ Released under the BSD-license.
 # Imports
 # -------
 
-from threading import Condition, Lock, currentThread
+from threading import Condition, currentThread, Lock
 from time import time
 
+
 # Read write lock
 # ---------------
 
diff --git a/wsgidav/samples/dav_provider_tools.py b/wsgidav/samples/dav_provider_tools.py
index 49b9f7e..392766f 100644
--- a/wsgidav/samples/dav_provider_tools.py
+++ b/wsgidav/samples/dav_provider_tools.py
@@ -4,11 +4,12 @@
 """
 Tools that make it easier to implement custom WsgiDAV providers.
 """
+from wsgidav import compat, util
+from wsgidav.dav_provider import DAVCollection, DAVNonCollection
+
 import os
 import stat
 
-from wsgidav import compat, util
-from wsgidav.dav_provider import DAVCollection, DAVNonCollection
 
 __docformat__ = "reStructuredText en"
 
diff --git a/wsgidav/samples/hg_dav_provider.py b/wsgidav/samples/hg_dav_provider.py
index d077a3c..d8696aa 100644
--- a/wsgidav/samples/hg_dav_provider.py
+++ b/wsgidav/samples/hg_dav_provider.py
@@ -72,17 +72,17 @@ Requirements:
     http://mercurial.berkwood.com/binaries/mercurial-1.4.win32-py2.6.exe
 """
 from __future__ import print_function
+from hashlib import md5
+from pprint import pprint
+from wsgidav import compat, util
+from wsgidav.dav_error import DAVError, HTTP_FORBIDDEN
+from wsgidav.dav_provider import _DAVResource, DAVProvider
+from wsgidav.samples.dav_provider_tools import VirtualCollection
 
 import os
 import sys
 import time
-from hashlib import md5
-from pprint import pprint
 
-from wsgidav import compat, util
-from wsgidav.dav_error import HTTP_FORBIDDEN, DAVError
-from wsgidav.dav_provider import DAVProvider, _DAVResource
-from wsgidav.samples.dav_provider_tools import VirtualCollection
 
 try:
     import mercurial.ui
diff --git a/wsgidav/samples/mongo_dav_provider.py b/wsgidav/samples/mongo_dav_provider.py
index 625fd71..3175821 100644
--- a/wsgidav/samples/mongo_dav_provider.py
+++ b/wsgidav/samples/mongo_dav_provider.py
@@ -24,14 +24,15 @@ Valid options are (sample shows defaults)::
             }
 
 """
-from pprint import pformat
-
-import pymongo
 from bson.objectid import ObjectId
+from pprint import pformat
 from wsgidav import compat, util
 from wsgidav.dav_provider import DAVCollection, DAVNonCollection, DAVProvider
 from wsgidav.util import join_uri
 
+import pymongo
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/samples/mysql_dav_provider.py b/wsgidav/samples/mysql_dav_provider.py
index 15015cb..3ac1ba6 100644
--- a/wsgidav/samples/mysql_dav_provider.py
+++ b/wsgidav/samples/mysql_dav_provider.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # (c) 2009-2018 Martin Wendt and contributors; see WsgiDAV https://github.com/mar10/wsgidav
 # Original PyFileServer (c) 2005 Ho Chun Wei.
 # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
@@ -57,21 +58,19 @@ its limitations:
 
 """
 from __future__ import print_function
+from wsgidav import compat, util
+from wsgidav.dav_error import (
+    DAVError,
+    HTTP_FORBIDDEN,
+    PRECONDITION_CODE_ProtectedProperty,
+)
+from wsgidav.dav_provider import _DAVResource, DAVProvider
 
 import csv
 import hashlib
-
-# import md5
+import MySQLdb  # @UnresolvedImport
 import time
 
-import MySQLdb  # @UnresolvedImport
-from wsgidav import compat, util
-from wsgidav.dav_error import (
-    HTTP_FORBIDDEN,
-    DAVError,
-    PRECONDITION_CODE_ProtectedProperty,
-)
-from wsgidav.dav_provider import DAVProvider, _DAVResource
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/samples/virtual_dav_provider.py b/wsgidav/samples/virtual_dav_provider.py
index d9c3ad5..cb7e3fa 100644
--- a/wsgidav/samples/virtual_dav_provider.py
+++ b/wsgidav/samples/virtual_dav_provider.py
@@ -95,19 +95,20 @@ When accessed using WebDAV, the following URLs both return the same resource
     <share>/by_tag/hot/My doc 1
     <share>/by_key/1
 """
-import os
-import stat
-
 from wsgidav import compat, util
 from wsgidav.dav_error import (
+    DAVError,
     HTTP_FORBIDDEN,
     HTTP_INTERNAL_ERROR,
-    DAVError,
     PRECONDITION_CODE_ProtectedProperty,
 )
 from wsgidav.dav_provider import DAVCollection, DAVNonCollection, DAVProvider
 from wsgidav.util import join_uri
 
+import os
+import stat
+
+
 __docformat__ = "reStructuredText en"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/server/ext_wsgiutils_server.py b/wsgidav/server/ext_wsgiutils_server.py
index ccdf3a9..e41707f 100644
--- a/wsgidav/server/ext_wsgiutils_server.py
+++ b/wsgidav/server/ext_wsgiutils_server.py
@@ -53,6 +53,8 @@ can copy ``ext_wsgi_server.py`` to ``<Paste-installation>/paste/servers`` and us
 run the application by specifying ``server='ext_wsgiutils'`` in the ``server.conf`` or appropriate
 paste configuration.
 """
+from wsgidav import __version__, compat, util
+
 import logging
 import socket
 import sys
@@ -60,7 +62,6 @@ import threading
 import time
 import traceback
 
-from wsgidav import __version__, compat, util
 
 __docformat__ = "reStructuredText"
 
@@ -336,7 +337,7 @@ class ExtServer(socketserver.ThreadingMixIn, BaseHTTPServer.HTTPServer):
 
         #        # Flag stop request
         self.stop_request = True
-        time.sleep(.1)
+        time.sleep(0.1)
         if self.stopped:
             # _logger.info "stop_serve_forever() 'stopped'."
             return
diff --git a/wsgidav/server/run_reloading_server.py b/wsgidav/server/run_reloading_server.py
index 930a8ad..184aa60 100644
--- a/wsgidav/server/run_reloading_server.py
+++ b/wsgidav/server/run_reloading_server.py
@@ -6,10 +6,10 @@ Wrapper for ``server_cli``, that restarts the server when source code is
 modified.
 """
 from __future__ import print_function
+from subprocess import Popen
 
 import os
 import sys
-from subprocess import Popen
 
 
 def run():
diff --git a/wsgidav/server/server_cli.py b/wsgidav/server/server_cli.py
index 33d61db..c56b1be 100644
--- a/wsgidav/server/server_cli.py
+++ b/wsgidav/server/server_cli.py
@@ -33,6 +33,14 @@ Configuration is defined like this:
        FOLDER on the '/' share.
 """
 from __future__ import print_function
+from inspect import isfunction
+from jsmin import jsmin
+from pprint import pformat
+from wsgidav import __version__, util
+from wsgidav.default_conf import DEFAULT_CONFIG, DEFAULT_VERBOSE
+from wsgidav.fs_dav_provider import FilesystemProvider
+from wsgidav.wsgidav_app import WsgiDAVApp
+from wsgidav.xml_tools import use_lxml
 
 import argparse
 import copy
@@ -43,17 +51,8 @@ import os
 import platform
 import sys
 import traceback
-from inspect import isfunction
-from pprint import pformat
-
 import yaml
-from jsmin import jsmin
 
-from wsgidav import __version__, util
-from wsgidav.default_conf import DEFAULT_CONFIG, DEFAULT_VERBOSE
-from wsgidav.fs_dav_provider import FilesystemProvider
-from wsgidav.wsgidav_app import WsgiDAVApp
-from wsgidav.xml_tools import use_lxml
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/server/server_sample.py b/wsgidav/server/server_sample.py
index b511a6d..133e714 100644
--- a/wsgidav/server/server_sample.py
+++ b/wsgidav/server/server_sample.py
@@ -6,13 +6,12 @@
 Simple example how to a run WsgiDAV in a 3rd-party WSGI server.
 """
 from __future__ import print_function
-
 from tempfile import gettempdir
-
 from wsgidav import __version__
 from wsgidav.fs_dav_provider import FilesystemProvider
 from wsgidav.wsgidav_app import WsgiDAVApp
 
+
 __docformat__ = "reStructuredText"
 
 
diff --git a/wsgidav/stream_tools.py b/wsgidav/stream_tools.py
index c4f70b3..2fba615 100644
--- a/wsgidav/stream_tools.py
+++ b/wsgidav/stream_tools.py
@@ -17,9 +17,9 @@ consumer at the same time::
 
 """
 from __future__ import print_function
-
 from wsgidav import compat, util
 
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/util.py b/wsgidav/util.py
index 76bba9f..86778e5 100644
--- a/wsgidav/util.py
+++ b/wsgidav/util.py
@@ -6,6 +6,23 @@
 """
 Miscellaneous support functions for WsgiDAV.
 """
+from email.utils import formatdate, parsedate
+from hashlib import md5
+from pprint import pformat
+from wsgidav import compat
+from wsgidav.dav_error import (
+    as_DAVError,
+    DAVError,
+    get_http_status_string,
+    HTTP_BAD_REQUEST,
+    HTTP_CREATED,
+    HTTP_NO_CONTENT,
+    HTTP_NOT_MODIFIED,
+    HTTP_OK,
+    HTTP_PRECONDITION_FAILED,
+)
+from wsgidav.xml_tools import etree, is_etree_element, make_sub_element, xml_to_bytes
+
 import base64
 import calendar
 import collections
@@ -17,23 +34,7 @@ import socket
 import stat
 import sys
 import time
-from email.utils import formatdate, parsedate
-from hashlib import md5
-from pprint import pformat
 
-from wsgidav import compat
-from wsgidav.dav_error import (
-    HTTP_BAD_REQUEST,
-    HTTP_CREATED,
-    HTTP_NO_CONTENT,
-    HTTP_NOT_MODIFIED,
-    HTTP_OK,
-    HTTP_PRECONDITION_FAILED,
-    DAVError,
-    as_DAVError,
-    get_http_status_string,
-)
-from wsgidav.xml_tools import etree, is_etree_element, make_sub_element, xml_to_bytes
 
 __docformat__ = "reStructuredText"
 
diff --git a/wsgidav/wsgidav_app.py b/wsgidav/wsgidav_app.py
index add168c..f2f908a 100644
--- a/wsgidav/wsgidav_app.py
+++ b/wsgidav/wsgidav_app.py
@@ -48,13 +48,7 @@ For every request:
     Note: The OPTIONS method for the '*' path is handled directly.
 
 """
-import copy
-import inspect
-import platform
-import sys
-import time
-
-from wsgidav import compat, util, __version__
+from wsgidav import __version__, compat, util
 from wsgidav.dav_provider import DAVProvider
 from wsgidav.default_conf import DEFAULT_CONFIG
 from wsgidav.fs_dav_provider import FilesystemProvider
@@ -69,6 +63,13 @@ from wsgidav.util import (
     safe_re_encode,
 )
 
+import copy
+import inspect
+import platform
+import sys
+import time
+
+
 __docformat__ = "reStructuredText"
 
 _logger = util.get_module_logger(__name__)
diff --git a/wsgidav/xml_tools.py b/wsgidav/xml_tools.py
index aa79394..6fa8416 100644
--- a/wsgidav/xml_tools.py
+++ b/wsgidav/xml_tools.py
@@ -8,9 +8,10 @@ Small wrapper for different etree packages.
 """
 # from __future__ import print_function
 
+from wsgidav import compat
+
 import logging
 
-from wsgidav import compat
 
 __docformat__ = "reStructuredText"