remove six.add_metaclass usage

certbot-apache/certbot_apache/_internal/interfaces.py

@@ -100,12 +100,10 @@ For this reason the internal representation of data should not ignore the case.
 """
 
 import abc
-import six
 
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ParserNode(object):
+class ParserNode(object, metaclass=abc.ABCMeta):
     """
     ParserNode is the basic building block of the tree of such nodes,
     representing the structure of the configuration. It is largely meant to keep
@@ -204,9 +202,7 @@ class ParserNode(object):
         """
 
 
-# Linter rule exclusion done because of https://github.com/PyCQA/pylint/issues/179
-@six.add_metaclass(abc.ABCMeta)  # pylint: disable=abstract-method
-class CommentNode(ParserNode):
+class CommentNode(ParserNode, metaclass=abc.ABCMeta):
     """
     CommentNode class is used for representation of comments within the parsed
     configuration structure. Because of the nature of comments, it is not able
@@ -249,8 +245,7 @@ class CommentNode(ParserNode):
                                           metadata=kwargs.get('metadata', {}))  # pragma: no cover
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DirectiveNode(ParserNode):
+class DirectiveNode(ParserNode, metaclass=abc.ABCMeta):
     """
     DirectiveNode class represents a configuration directive within the configuration.
     It can have zero or more parameters attached to it. Because of the nature of
@@ -325,8 +320,7 @@ class DirectiveNode(ParserNode):
         """
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BlockNode(DirectiveNode):
+class BlockNode(DirectiveNode, metaclass=abc.ABCMeta):
     """
     BlockNode class represents a block of nested configuration directives, comments
     and other blocks as its children. A BlockNode can have zero or more parameters

certbot/certbot/interfaces.py

@@ -1,14 +1,12 @@
 """Certbot client interfaces."""
 import abc
 
-import six
 import zope.interface
 
 # pylint: disable=no-self-argument,no-method-argument,inherit-non-class
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AccountStorage(object):
+class AccountStorage(object, metaclass=abc.ABCMeta):
     """Accounts storage interface."""
 
     @abc.abstractmethod
@@ -547,8 +545,7 @@ class IReporter(zope.interface.Interface):
         """Prints messages to the user and clears the message queue."""
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RenewableCert(object):
+class RenewableCert(object, metaclass=abc.ABCMeta):
     """Interface to a certificate lineage."""
 
     @abc.abstractproperty
@@ -613,8 +610,7 @@ class RenewableCert(object):
 # an update during the run or install subcommand, it should do so when
 # :func:`IInstaller.deploy_cert` is called.
 
-@six.add_metaclass(abc.ABCMeta)
-class GenericUpdater(object):
+class GenericUpdater(object, metaclass=abc.ABCMeta):
     """Interface for update types not currently specified by Certbot.
 
     This class allows plugins to perform types of updates that Certbot hasn't
@@ -646,8 +642,7 @@ class GenericUpdater(object):
         """
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RenewDeployer(object):
+class RenewDeployer(object, metaclass=abc.ABCMeta):
     """Interface for update types run when a lineage is renewed
 
     This class allows plugins to perform types of updates that need to run at

certbot/certbot/plugins/enhancements.py

@@ -1,8 +1,6 @@
 """New interface style Certbot enhancements"""
 import abc
 
-import six
-
 from acme.magic_typing import Any
 from acme.magic_typing import Dict
 from acme.magic_typing import List
@@ -91,8 +89,7 @@ def populate_cli(add):
             help=enh["cli_help"])
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AutoHSTSEnhancement(object):
+class AutoHSTSEnhancement(object, metaclass=abc.ABCMeta):
     """
     Enhancement interface that installer plugins can implement in order to
     provide functionality that configures the software to have a