Move flake8 configuration to its own file and activate some plugins

.flake8

@@ -0,0 +1,28 @@
+[flake8]
+#format = pylint
+ignore =
+  A003, # attribute overriding builtin name
+  B006, # [bugbear] Do not use mutable data structures for argument defaults (I choose by myself)
+  E123, # closing bracket does not match indentation of opening bracket's line (disagree with emacs python mode)
+  E126, # continuation line over-indented for hanging indent line (disagree with emacs python mode)
+  E226, # missing whitespace around arithmetic operator (disagree when in parameter)
+  P101, # [string-format] format string does contain unindexed parameters (don't care of py2.6)
+  P103, # [string-format] other string does contain unindexed parameters
+  P102, # [string-format] docstring does contain unindexed parameters
+  W503, # Line break occurred before a binary operator (to keep operators aligned)
+
+max-line-length = 80
+exclude = doc/*,.tox/*,.eggs,test/data
+#import-order-style = google
+#application-import-names=lowatt_core
+rst-roles =
+  class,
+  envvar,
+  func,
+  meth,
+  ref,
+rst-directives =
+  autoattribute,
+  autoclass,
+  autofunction,
+  automethod,

MANIFEST.in

@@ -1,3 +1,4 @@
+include .flake8
 include requirements.txt
 include pytest.ini
 include tox.ini

pdfss.py

@@ -262,7 +262,7 @@ def default_group_line(linfo, latest_linfo):
         diff = abs(latest_linfo.font_size - linfo.font_size)
         if ((linfo.font_name.endswith('-bold')
              and not latest_linfo.font_name.endswith('-bold'))
-            or
+            or  # noqa
             (latest_linfo.font_name.endswith('-bold')
              and not linfo.font_name.endswith('-bold'))):
             allowed_y_diff = diff * 1.5
@@ -311,15 +311,15 @@ def default_iter_text(ltobj, skip_classes=None):
         yield ltobj
 
     else:
-        assert False, ltobj
+        raise RuntimeError("Unexpected object", ltobj)
 
 
 def relayout(
         ltobj, skip_classes=DEFAULT_SKIP_CLASSES, skip_text=None,
         iter_text=default_iter_text,
         ltchar_filter=None,
-        merge_text=default_text_merger(),
-        group_line=default_line_grouper(),
+        merge_text=default_text_merger(),  # noqa
+        group_line=default_line_grouper(),  # noqa
 ):
     """Return a list of :class:LinesGroup for given PDFMiner `ltobj` instance.
 

tox.ini

@@ -17,10 +17,20 @@ commands =
   {envpython} -m unittest discover -s test -c {posargs}
 
 [testenv:flake8]
-skip_install = true
 deps =
   flake8
-changedir={toxinidir}
+  flake8-blind-except
+  flake8-bugbear
+  flake8-builtins
+  flake8-commas
+  flake8-comprehensions
+  flake8-debugger
+  flake8-logging-format
+  flake8-rst-docstrings
+  flake8-pep3101
+  #flake8-print
+  flake8-string-format
+skip_install = true
 commands = flake8
 
 [testenv:check-manifest]
@@ -29,9 +39,3 @@ deps =
   check-manifest
 commands =
   {envpython} -m check_manifest {toxinidir}
-
-[flake8]
-#format = pylint
-#ignore = W503
-max-line-length = 80
-exclude = doc/*,.tox/*,test/data/*