Fix Pylint upgrade issues

* Remove unsupported pylint disable options
    * star-args removed in Pylint 1.4.3
    * abstract-class-little-used removed in Pylint 1.4.3

* Fixes new lint errors

* Copy dummy-variable-rgx expression to new ignored-argument-names expression to ignore unused funtion arguments

* Notable changes
    * Refactor to satisfy Pylint no-else-return warning
    * Fix Pylint inconsistent-return-statements warning
    * Refactor to satisfy consider-iterating-dictionary
    * Remove methods with only super call to satisfy useless-super-delegation
    * Refactor too-many-nested-statements where possible
    * Suppress type checked errors where member is dynamically added (notably derived from josepy.JSONObjectWithFields)
    * Remove None default of func parameter for ExitHandler and ErrorHandler

Resolves #5973

certbot/plugins/common.py

@@ -299,9 +299,8 @@ class Addr(object):
             # too long, truncate
             addr_list = addr_list[0:len(result)]
         append_to_end = False
-        for i in range(0, len(addr_list)):
-            block = addr_list[i]
-            if len(block) == 0:
+        for i, block in enumerate(addr_list):
+            if not block:
                 # encountered ::, so rest of the blocks should be
                 # appended to the end
                 append_to_end = True

certbot/plugins/disco.py

@@ -2,11 +2,10 @@
 import collections
 import itertools
 import logging
+
 import pkg_resources
 import six
 
-from collections import OrderedDict
-
 import zope.interface
 import zope.interface.verify
 
@@ -184,7 +183,11 @@ class PluginsRegistry(collections.Mapping):
         # This prevents deadlock caused by plugins acquiring a lock
         # and ensures at least one concurrent Certbot instance will run
         # successfully.
-        self._plugins = OrderedDict(sorted(six.iteritems(plugins)))
+
+        # Pylint checks for super init, but also claims the super
+        # has no __init__member
+        # pylint: disable=super-init-not-called
+        self._plugins = collections.OrderedDict(sorted(six.iteritems(plugins)))
 
     @classmethod
     def find_all(cls):
@@ -233,7 +236,6 @@ class PluginsRegistry(collections.Mapping):
 
     def ifaces(self, *ifaces_groups):
         """Filter plugins based on interfaces."""
-        # pylint: disable=star-args
         return self.filter(lambda p_ep: p_ep.ifaces(*ifaces_groups))
 
     def verify(self, ifaces):
@@ -269,8 +271,7 @@ class PluginsRegistry(collections.Mapping):
         assert len(candidates) <= 1
         if candidates:
             return candidates[0]
-        else:
-            return None
+        return None
 
     def __repr__(self):
         return "{0}({1})".format(

certbot/plugins/dns_common.py

@@ -83,7 +83,7 @@ class DNSAuthenticator(common.Plugin):
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def _perform(self, domain, validation_domain_name, validation):  # pragma: no cover
+    def _perform(self, domain, validation_name, validation):  # pragma: no cover
         """
         Performs a dns-01 challenge by creating a DNS TXT record.
 
@@ -95,7 +95,7 @@ class DNSAuthenticator(common.Plugin):
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def _cleanup(self, domain, validation_domain_name, validation):  # pragma: no cover
+    def _cleanup(self, domain, validation_name, validation):  # pragma: no cover
         """
         Deletes the DNS TXT record which would have been created by `_perform_achall`.
 

certbot/plugins/dns_common_lexicon.py

@@ -95,3 +95,4 @@ class LexiconClient(object):
         if not str(e).startswith('No domain found'):
             return errors.PluginError('Unexpected error determining zone identifier for {0}: {1}'
                                       .format(domain_name, e))
+        return None

certbot/plugins/dns_common_test.py

@@ -22,10 +22,6 @@ class DNSAuthenticatorTest(util.TempDirTestCase, dns_test_common.BaseAuthenticat
         _perform = mock.MagicMock()
         _cleanup = mock.MagicMock()
 
-        def __init__(self, *args, **kwargs):
-            # pylint: disable=protected-access
-            super(DNSAuthenticatorTest._FakeDNSAuthenticator, self).__init__(*args, **kwargs)
-
         def more_info(self):  # pylint: disable=missing-docstring,no-self-use
             return 'A fake authenticator for testing.'
 

certbot/plugins/manual_test.py

@@ -137,8 +137,7 @@ class AuthenticatorTest(test_util.TempDirTestCase):
             self.auth.cleanup([achall])
             self.assertEqual(os.environ['CERTBOT_AUTH_OUTPUT'], 'foo')
             self.assertEqual(os.environ['CERTBOT_DOMAIN'], achall.domain)
-            if (isinstance(achall.chall, challenges.HTTP01) or
-                isinstance(achall.chall, challenges.DNS01)):
+            if isinstance(achall.chall, (challenges.HTTP01, challenges.DNS01)):
                 self.assertEqual(
                     os.environ['CERTBOT_VALIDATION'],
                     achall.validation(achall.account_key))

certbot/plugins/selection.py

@@ -82,8 +82,7 @@ def pick_plugin(config, default, plugins, question, ifaces):
         plugin_ep = choose_plugin(list(six.itervalues(prepared)), question)
         if plugin_ep is None:
             return None
-        else:
-            return plugin_ep.init()
+        return plugin_ep.init()
     elif len(prepared) == 1:
         plugin_ep = list(prepared.values())[0]
         logger.debug("Single candidate plugin: %s", plugin_ep)

certbot/plugins/standalone.py

@@ -225,7 +225,8 @@ class Authenticator(common.Plugin):
             try:
                 return self._perform_single(achall)
             except errors.StandaloneBindError as error:
-                _handle_perform_error(error)
+                if not _handle_perform_error(error):
+                    raise
 
     def _perform_single(self, achall):
         if isinstance(achall.chall, challenges.HTTP01):
@@ -282,5 +283,5 @@ def _handle_perform_error(error):
                                      "Cancel", default=False)
         if not should_retry:
             raise errors.PluginError(msg)
-    else:
-        raise
+        return True
+    return False

certbot/plugins/storage_test.py

@@ -1,8 +1,8 @@
 """Tests for certbot.plugins.storage.PluginStorage"""
 import json
-import mock
 import os
 import unittest
+import mock
 
 from certbot import errors
 

certbot/plugins/util.py

@@ -17,7 +17,7 @@ def get_prefixes(path):
     """
     prefix = path
     prefixes = []
-    while len(prefix) > 0:
+    while prefix:
         prefixes.append(prefix)
         prefix, _ = os.path.split(prefix)
         # break once we hit '/'
@@ -49,8 +49,7 @@ def path_surgery(cmd):
 
     if util.exe_exists(cmd):
         return True
-    else:
-        expanded = " expanded" if any(added) else ""
-        logger.warning("Failed to find executable %s in%s PATH: %s", cmd,
-                       expanded, path)
-        return False
+    expanded = " expanded" if any(added) else ""
+    logger.warning("Failed to find executable %s in%s PATH: %s", cmd,
+                   expanded, path)
+    return False

certbot/plugins/webroot.py

@@ -220,7 +220,7 @@ to serve all files under specified web root ({0})."""
                 self.performed[root_path].remove(achall)
 
         not_removed = []
-        while len(self._created_dirs) > 0:
+        while self._created_dirs:
             path = self._created_dirs.pop()
             try:
                 os.rmdir(path)