Migrate to pycodestyle and setup a basic config file

Signed-off-by: Niels Thykier <niels@thykier.net>

.gitlab-ci.yml

@@ -3,7 +3,7 @@ tests-stretch:
   image: debian:stretch
   script:
     - apt-get update
-    - apt-get install -y python3 python3-apt python3-yaml python3-pep8 python3-pytest git rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl
+    - apt-get install -y python3 python3-apt python3-yaml python3-pycodestyle python3-pytest git rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl
     - ci/gitlab-ci-runner
 
 tests-sid:
@@ -11,7 +11,7 @@ tests-sid:
   image: debian:sid
   script:
     - apt-get update
-    - apt-get install -y python3 python3-apt python3-yaml python3-coverage python3-pep8 python3-pytest python3-pytest-cov git rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl
+    - apt-get install -y python3 python3-apt python3-yaml python3-coverage python3-pycodestyle python3-pytest python3-pytest-cov git rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl
     - ci/gitlab-ci-runner --with-coverage
   artifacts:
     paths:

Dockerfile

@@ -1,4 +1,4 @@
 FROM debian:stable
 WORKDIR /britney
 ADD . /britney
-RUN apt-get update && apt-get install --no-install-recommends --assume-yes python3 python3-apt python3-yaml python3-coverage python3-nose python3-pep8 rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl curl
+RUN apt-get update && apt-get install --no-install-recommends --assume-yes python3 python3-apt python3-yaml python3-coverage python3-nose python3-pycodestyle rsync libclass-accessor-perl libdpkg-perl libyaml-syck-perl curl

setup.cfg

@@ -0,0 +1,6 @@
+[pycodestyle]
+count = False
+#ignore = E226,E302,E41
+# 120 is the limit but leave 10% buffer for minor transgressions.
+max-line-length = 130
+statistics = True

tests/test_pycodestyle.py

@@ -1,12 +1,15 @@
+import os
 import unittest
-import pep8
+import pycodestyle
 
 
 class TestCodeFormat(unittest.TestCase):
 
     def test_conformance(self):
         """Test that we conform to PEP-8."""
-        style = pep8.StyleGuide()
+        project_dir = os.path.dirname(os.path.dirname(__file__))
+        codestyle_cfg = os.path.join(project_dir, 'setup.cfg')
+        style = pycodestyle.StyleGuide(config_file=codestyle_cfg)
         result = style.check_files('.')
         self.assertEqual(result.total_errors, 0,
                          "Found code style errors (and warnings).")