Merge ~cjwatson/lazr.restful:pyupgrade-py3 into lazr.restful:main

[Colin Watson]

Apply pyupgrade --py3-plus

[Jürgen Gmach (jugmac00)]

LGTM with a minor issue, see comment

review: Approve

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 6f75344..6b363b1 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -23,7 +23,7 @@ repos:
     rev: v2.29.0
     hooks:
     -   id: pyupgrade
-        args: [--keep-percent-format]
+        args: [--keep-percent-format, --py3-plus]
 -   repo: https://github.com/psf/black
     rev: 21.10b0
     hooks:
diff --git a/pyproject.toml b/pyproject.toml
index 486bbe6..1f331da 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,3 @@
 [tool.black]
 line-length = 79
-target-version = ['py27']
+target-version = ['py35']
diff --git a/src/lazr/restful/__init__.py b/src/lazr/restful/__init__.py
index 25235cd..c8e3f40 100644
--- a/src/lazr/restful/__init__.py
+++ b/src/lazr/restful/__init__.py
@@ -17,8 +17,6 @@
 
 # pylint: disable-msg=W0401
 
-from __future__ import absolute_import, print_function
-
 try:
     import importlib.metadata as importlib_metadata
 except ImportError:
diff --git a/src/lazr/restful/_bytestorage.py b/src/lazr/restful/_bytestorage.py
index 7d6c6a0..b25369c 100644
--- a/src/lazr/restful/_bytestorage.py
+++ b/src/lazr/restful/_bytestorage.py
@@ -16,9 +16,6 @@
 
 """Classes for a resource that implements a binary file repository."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "ByteStorageResource",
 ]
diff --git a/src/lazr/restful/_operation.py b/src/lazr/restful/_operation.py
index af48e48..7cab8ea 100644
--- a/src/lazr/restful/_operation.py
+++ b/src/lazr/restful/_operation.py
@@ -2,10 +2,7 @@
 
 """Base classes for one-off HTTP operations."""
 
-from __future__ import absolute_import, print_function
-
 import simplejson
-import six
 
 from zope.component import getMultiAdapter, getUtility, queryMultiAdapter
 from zope.event import notify
@@ -40,7 +37,6 @@ from lazr.restful._resource import (
 )
 
 
-__metaclass__ = type
 __all__ = [
     "IObjectLink",
     "ObjectLink",
@@ -163,9 +159,7 @@ class ResourceOperation(BatchingResourceMixin):
             # has its response batched.
             return True
 
-        if zope_isinstance(
-            result, (bytes, six.text_type, dict, set, list, tuple)
-        ):
+        if zope_isinstance(result, (bytes, str, dict, set, list, tuple)):
             # Ordinary Python data structures generally are not
             # batched.
             return False
@@ -216,14 +210,14 @@ class ResourceOperation(BatchingResourceMixin):
                         self.request.form.get(name)
                     )
                 except ValueError as e:
-                    errors.append(u"%s: %s" % (name, e))
+                    errors.append("%s: %s" % (name, e))
                     continue
             try:
                 field.validate(value)
             except RequiredMissing:
-                errors.append(u"%s: Required input is missing." % name)
+                errors.append("%s: Required input is missing." % name)
             except ValidationError as e:
-                errors.append(u"%s: %s" % (name, e))
+                errors.append("%s: %s" % (name, e))
             else:
                 validated_values[name] = value
         return (validated_values, errors)
@@ -252,7 +246,7 @@ class IObjectLink(IField):
     """Field containing a link to an object."""
 
     schema = Attribute(
-        "schema", u"The Interface of the Object on the other end of the link."
+        "schema", "The Interface of the Object on the other end of the link."
     )
 
 
@@ -265,4 +259,4 @@ class ObjectLink(Field):
             raise WrongType
 
         self.schema = schema
-        super(ObjectLink, self).__init__(**kw)
+        super().__init__(**kw)
diff --git a/src/lazr/restful/_resource.py b/src/lazr/restful/_resource.py
index f01326d..45f717e 100644
--- a/src/lazr/restful/_resource.py
+++ b/src/lazr/restful/_resource.py
@@ -2,10 +2,6 @@
 
 """Base classes for HTTP resources."""
 
-from __future__ import absolute_import, division, print_function
-
-__metaclass__ = type
-
 __all__ = [
     "BatchingResourceMixin",
     "Collection",
@@ -55,7 +51,6 @@ try:
 except ImportError:
     from cgi import escape
 
-import six
 from zope.component import (
     adapter,
     getAdapters,
@@ -162,7 +157,7 @@ init_status_codes()
 
 def decode_value(value):
     """Return a unicode value curresponding to `value`."""
-    if isinstance(value, six.text_type):
+    if isinstance(value, str):
         return value
     elif isinstance(value, bytes):
         return value.decode("utf-8")
@@ -172,7 +167,7 @@ def decode_value(value):
 
 def _default_html_renderer(value):
     """The default technique for rendering a value as an HTML snippet."""
-    return escape(six.text_type(value), quote=False)
+    return escape(str(value), quote=False)
 
 
 @adapter(Interface, IField, IWebServiceClientRequest)
@@ -212,7 +207,7 @@ class ResourceJSONEncoder(simplejson.encoder.JSONEncoderForHTML):
 
     def __init__(self, *args, **kwargs):
         self.media_type = kwargs.pop("media_type", HTTPResource.JSON_TYPE)
-        super(ResourceJSONEncoder, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def default(self, obj):
         """Convert the given object to a simple data structure."""
@@ -711,7 +706,7 @@ class CustomOperationResourceMixin:
         # with multiple inheritance. That requires defining __init__
         # to call the next constructor in the chain, which means using
         # super() even though this class itself has no superclass.
-        super(CustomOperationResourceMixin, self).__init__(context, request)
+        super().__init__(context, request)
 
     def handleCustomGET(self, operation_name):
         """Execute a custom search-type operation triggered through GET.
@@ -722,7 +717,7 @@ class CustomOperationResourceMixin:
         :return: The result of the operation: either a string or an
         object that needs to be serialized to JSON.
         """
-        if not isinstance(operation_name, six.string_types):
+        if not isinstance(operation_name, str):
             self.request.response.setStatus(400)
             return "Expected a single operation: %r" % (operation_name,)
 
@@ -750,7 +745,7 @@ class CustomOperationResourceMixin:
         :return: The result of the operation: either a string or an
         object that needs to be serialized to JSON.
         """
-        if not isinstance(operation_name, six.string_types):
+        if not isinstance(operation_name, str):
             self.request.response.setStatus(400)
             return "Expected a single operation: %r" % (operation_name,)
 
@@ -810,7 +805,7 @@ class FieldUnmarshallerMixin:
         # with multiple inheritance. That requires defining __init__
         # to call the next constructor in the chain, which means using
         # super() even though this class itself has no superclass.
-        super(FieldUnmarshallerMixin, self).__init__(context, request)
+        super().__init__(context, request)
         self._unmarshalled_field_cache = {}
 
     def _unmarshallField(self, field_name, field, detail=NORMAL_DETAIL):
@@ -909,7 +904,7 @@ class ReadOnlyResource(HTTPResource):
         # This class is designed to be used with mixins. That means
         # defining __init__ to call the next constructor in the chain,
         # even though there's no other code in __init__.
-        super(ReadOnlyResource, self).__init__(context, request)
+        super().__init__(context, request)
 
     def __call__(self):
         """Handle a GET or (if implemented) POST request."""
@@ -936,7 +931,7 @@ class ReadWriteResource(HTTPResource):
         # This class is designed to be used with mixins. That means
         # defining __init__ to call the next constructor in the chain,
         # even though there's no other code in __init__.
-        super(ReadWriteResource, self).__init__(context, request)
+        super().__init__(context, request)
 
     def __call__(self):
         """Handle a GET, PUT, or PATCH request."""
@@ -980,10 +975,7 @@ class ReadWriteResource(HTTPResource):
                     # hopefully handle it better.  Note the careful
                     # reraising that ensures the original traceback is
                     # preserved.
-                    if six.PY3:
-                        six.raise_from(exception_info[1], None)
-                    else:
-                        six.reraise(*exception_info)
+                    raise exception_info[1] from None
             finally:
                 del exception_info
 
@@ -1035,7 +1027,7 @@ class EntryManipulatingResource(ReadWriteResource):
         # This class is designed to be used with mixins. That means
         # defining __init__ to call the next constructor in the chain,
         # even though there's no other code in __init__.
-        super(EntryManipulatingResource, self).__init__(context, request)
+        super().__init__(context, request)
 
     def processAsJSONDocument(self, media_type, representation):
         """Process an incoming representation as a JSON document."""
@@ -1066,7 +1058,7 @@ class EntryManipulatingResource(ReadWriteResource):
         # Some fields aren't part of the schema, so they're handled
         # separately.
         modified_read_only_attribute = (
-            u"%s: You tried to modify a " "read-only attribute."
+            "%s: You tried to modify a " "read-only attribute."
         )
         if "self_link" in changeset:
             if changeset["self_link"] != absoluteURL(
@@ -1143,7 +1135,7 @@ class EntryManipulatingResource(ReadWriteResource):
             try:
                 value = marshaller.marshall_from_json_data(original_value)
             except (ValueError, ValidationError) as e:
-                errors.append(u"%s: %s" % (repr_name, e))
+                errors.append("%s: %s" % (repr_name, e))
                 continue
 
             if ICollectionField.providedBy(field):
@@ -1152,7 +1144,7 @@ class EntryManipulatingResource(ReadWriteResource):
                 # current one.
                 if value != current_value:
                     errors.append(
-                        u"%s: You tried to modify a collection "
+                        "%s: You tried to modify a collection "
                         "attribute." % repr_name
                     )
                 continue
@@ -1170,7 +1162,7 @@ class EntryManipulatingResource(ReadWriteResource):
                         errors.append(modified_read_only_attribute % repr_name)
                     else:
                         errors.append(
-                            u"%s: To modify this field you need to send a PUT "
+                            "%s: To modify this field you need to send a PUT "
                             "request to its URI (%s)."
                             % (repr_name, current_value)
                         )
@@ -1186,7 +1178,7 @@ class EntryManipulatingResource(ReadWriteResource):
                 # class the way IReference fields can.
                 if value is not None and not field.schema.providedBy(value):
                     errors.append(
-                        u"%s: Your value points to the "
+                        "%s: Your value points to the "
                         "wrong kind of object" % repr_name
                     )
                     continue
@@ -1215,22 +1207,20 @@ class EntryManipulatingResource(ReadWriteResource):
                     # the exception; otherwise use a generic message
                     # instead of whatever object the raise site
                     # thought would be a good idea.
-                    if len(e.args) > 0 and isinstance(
-                        e.args[0], six.string_types
-                    ):
+                    if len(e.args) > 0 and isinstance(e.args[0], str):
                         error = e.args[0]
                     else:
                         error = "Constraint not satisfied."
-                    errors.append(u"%s: %s" % (repr_name, error))
+                    errors.append("%s: %s" % (repr_name, error))
                     continue
                 except RequiredMissing:
                     error = "Missing required value."
-                    errors.append(u"%s: %s" % (repr_name, error))
+                    errors.append("%s: %s" % (repr_name, error))
                 except (ValueError, ValidationError) as e:
                     error = str(e)
                     if error == "":
                         error = "Validation error"
-                    errors.append(u"%s: %s" % (repr_name, error))
+                    errors.append("%s: %s" % (repr_name, error))
                     continue
                 validated_changeset.append((field, value))
         # If there are any fields left in the changeset, they're
@@ -1238,7 +1228,7 @@ class EntryManipulatingResource(ReadWriteResource):
         # schema. They're all errors.
         for invalid_field in changeset.keys():
             errors.append(
-                u"%s: You tried to modify a nonexistent "
+                "%s: You tried to modify a nonexistent "
                 "attribute." % invalid_field
             )
 
@@ -1331,7 +1321,7 @@ class EntryFieldResource(FieldUnmarshallerMixin, EntryManipulatingResource):
 
     def __init__(self, context, request):
         """Initialize with respect to a context and request."""
-        super(EntryFieldResource, self).__init__(context, request)
+        super().__init__(context, request)
         self.entry = self.context.entry
 
     def do_GET(self):
@@ -1367,7 +1357,7 @@ class EntryFieldResource(FieldUnmarshallerMixin, EntryManipulatingResource):
         # generating the representation might itself change across
         # versions.
         revno = getUtility(IWebServiceConfiguration).code_revision
-        return [core.encode("utf-8") for core in [revno, six.text_type(value)]]
+        return [core.encode("utf-8") for core in [revno, str(value)]]
 
     def _representation(self, media_type):
         """Create a representation of the field value."""
@@ -1454,13 +1444,13 @@ class EntryResource(
 
     def __init__(self, context, request):
         """Associate this resource with a specific object and request."""
-        super(EntryResource, self).__init__(context, request)
+        super().__init__(context, request)
         self.entry = getMultiAdapter((context, request), IEntry)
 
     def handleCustomPOST(self, operation_name):
         """See `CustomOperationResourceMixin`."""
         original_url = absoluteURL(self.entry.context, self.request)
-        value = super(EntryResource, self).handleCustomPOST(operation_name)
+        value = super().handleCustomPOST(operation_name)
         # We don't know what the custom operation might have done.
         # Remove this object from the representation cache, just to be
         # safe.
@@ -1617,7 +1607,7 @@ class EntryResource(
         operation_name = self.request.form.pop("ws.op", None)
         if operation_name is not None:
             result = self.handleCustomGET(operation_name)
-            if isinstance(result, (bytes, six.text_type)):
+            if isinstance(result, (bytes, str)):
                 # The custom operation took care of everything and
                 # just needs this string served to the client.
                 return result
@@ -1860,7 +1850,7 @@ class CollectionResource(
 
     def __init__(self, context, request):
         """Associate this resource with a specific object and request."""
-        super(CollectionResource, self).__init__(context, request)
+        super().__init__(context, request)
         if ICollection.providedBy(context):
             self.collection = context
         else:
@@ -1872,7 +1862,7 @@ class CollectionResource(
         operation_name = self.request.form.pop("ws.op", None)
         if operation_name is not None:
             result = self.handleCustomGET(operation_name)
-            if isinstance(result, (bytes, six.text_type)):
+            if isinstance(result, (bytes, str)):
                 # The custom operation took care of everything and
                 # just needs this string served to the client.
                 return result
@@ -1905,7 +1895,7 @@ class CollectionResource(
             entries = self.collection.find()
         if request is None:
             request = self.request
-        result = super(CollectionResource, self).batch(entries, request)
+        result = super().batch(entries, request)
         result += ', "resource_type_link" : ' + simplejson.dumps(self.type_url)
         return result
 
diff --git a/src/lazr/restful/debug.py b/src/lazr/restful/debug.py
index 0567455..ebcf526 100644
--- a/src/lazr/restful/debug.py
+++ b/src/lazr/restful/debug.py
@@ -2,9 +2,6 @@
 
 """Module docstring goes here."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = ["debug_proxy", "typename"]
 
 
diff --git a/src/lazr/restful/declarations.py b/src/lazr/restful/declarations.py
index 4c95bcd..f717592 100644
--- a/src/lazr/restful/declarations.py
+++ b/src/lazr/restful/declarations.py
@@ -2,9 +2,6 @@
 
 """Declaration helpers to define a web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "COLLECTION_TYPE",
     "ENTRY_TYPE",
@@ -1134,9 +1131,7 @@ class export_factory_operation(_export_operation):
 
     def annotate_method(self, method, annotations):
         """See `_method_annotator`."""
-        super(export_factory_operation, self).annotate_method(
-            method, annotations
-        )
+        super().annotate_method(method, annotations)
         annotations["creates"] = self.interface
         annotations["params"] = self.params
         annotations["return_type"] = ObjectLink(schema=self.interface)
@@ -1147,7 +1142,7 @@ class cache_for(_method_annotator):
 
     def __init__(self, duration):
         """Specify the duration, in seconds, of the caching resource."""
-        if not isinstance(duration, six.integer_types):
+        if not isinstance(duration, int):
             raise TypeError(
                 "Caching duration should be an integer type, not %s"
                 % duration.__class__.__name__
@@ -1174,7 +1169,7 @@ class scoped(_method_annotator):
 
     def __init__(self, *scopes):
         for scope in scopes:
-            if not isinstance(scope, six.string_types):
+            if not isinstance(scope, str):
                 raise TypeError(
                     "Scope should be a string type, not %s"
                     % scope.__class__.__name__
@@ -1214,9 +1209,7 @@ class export_destructor_operation(_export_operation):
 
         Every version must have a self-consistent set of annotations.
         """
-        super(export_destructor_operation, self).annotate_method(
-            method, annotation_stack
-        )
+        super().annotate_method(method, annotation_stack)
         # The mutator method must take no arguments, not counting
         # arguments with values fixed by call_with().
         for version, annotations in annotation_stack.stack:
@@ -1555,14 +1548,14 @@ class _ScopeChecker(Passthrough):
         if self.adaptation is not None:
             context = self.adaptation(context)
         _check_request(context, None)
-        return super(_ScopeChecker, self).__get__(inst, cls=cls)
+        return super().__get__(inst, cls=cls)
 
     def __set__(self, inst, value):
         context = getattr(inst, self.contextvar)
         if self.adaptation is not None:
             context = self.adaptation(context)
         _check_request(context, None)
-        return super(_ScopeChecker, self).__set__(inst, value)
+        return super().__set__(inst, value)
 
 
 class _AccessorWrapper:
@@ -1615,7 +1608,7 @@ class PropertyWithAccessor(_AccessorWrapper, _ScopeChecker):
     def __init__(
         self, name, context, accessor, accessor_annotations, adaptation
     ):
-        super(PropertyWithAccessor, self).__init__(name, context, adaptation)
+        super().__init__(name, context, adaptation)
         self.accessor = accessor.__name__
         self.accessor_annotations = accessor_annotations
 
@@ -1626,7 +1619,7 @@ class PropertyWithMutator(_MutatorWrapper, _ScopeChecker):
     def __init__(
         self, name, context, mutator, mutator_annotations, adaptation
     ):
-        super(PropertyWithMutator, self).__init__(name, context, adaptation)
+        super().__init__(name, context, adaptation)
         self.mutator = mutator.__name__
         self.mutator_annotations = mutator_annotations
 
@@ -1646,9 +1639,7 @@ class PropertyWithAccessorAndMutator(
         mutator_annotations,
         adaptation,
     ):
-        super(PropertyWithAccessorAndMutator, self).__init__(
-            name, context, adaptation
-        )
+        super().__init__(name, context, adaptation)
         self.accessor = accessor.__name__
         self.accessor_annotations = accessor_annotations
         self.mutator = mutator.__name__
@@ -1792,7 +1783,7 @@ class BaseFactoryResourceOperationAdapter(BaseResourceOperationAdapter):
         response = self.request.response
         response.setStatus(201)
         response.setHeader("Location", absoluteURL(result, self.request))
-        return u""
+        return ""
 
 
 def generate_operation_adapter(method, version=None):
diff --git a/src/lazr/restful/directives/__init__.py b/src/lazr/restful/directives/__init__.py
index 4db78d1..e311f8e 100644
--- a/src/lazr/restful/directives/__init__.py
+++ b/src/lazr/restful/directives/__init__.py
@@ -2,9 +2,6 @@
 
 """Martian directives used in lazr.restful."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "request_class",
     "publication_class",
diff --git a/src/lazr/restful/docs/conf.py b/src/lazr/restful/docs/conf.py
index bd3dea3..f1c692d 100644
--- a/src/lazr/restful/docs/conf.py
+++ b/src/lazr/restful/docs/conf.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-#
 # lazr.restful documentation build configuration file, created by
 # sphinx-quickstart on Sun Nov  3 15:00:52 2019.
 #
@@ -47,9 +45,9 @@ source_suffix = ".rst"
 master_doc = "index"
 
 # General information about the project.
-project = u"lazr.restful"
-copyright = u"2004-2019, Canonical Ltd."
-author = u"LAZR Developers <[e-mail]>"
+project = "lazr.restful"
+copyright = "2004-2019, Canonical Ltd."
+author = "LAZR Developers <[e-mail]>"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -140,8 +138,8 @@ latex_documents = [
     (
         master_doc,
         "lazrrestful.tex",
-        u"lazr.restful Documentation",
-        u"LAZR Developers \\textless{}[e-mail]\\textgreater{}",  # noqa: E501
+        "lazr.restful Documentation",
+        "LAZR Developers \\textless{}[e-mail]\\textgreater{}",  # noqa: E501
         "manual",
     ),
 ]
@@ -152,7 +150,7 @@ latex_documents = [
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 man_pages = [
-    (master_doc, "lazrrestful", u"lazr.restful Documentation", [author], 1)
+    (master_doc, "lazrrestful", "lazr.restful Documentation", [author], 1)
 ]
 
 
@@ -165,7 +163,7 @@ texinfo_documents = [
     (
         master_doc,
         "lazrrestful",
-        u"lazr.restful Documentation",
+        "lazr.restful Documentation",
         author,
         "lazrrestful",
         "One line description of project.",
diff --git a/src/lazr/restful/error.py b/src/lazr/restful/error.py
index 86cef16..a2cf44b 100644
--- a/src/lazr/restful/error.py
+++ b/src/lazr/restful/error.py
@@ -2,9 +2,6 @@
 
 """Error handling on the webservice."""
 
-from __future__ import absolute_import, division, print_function
-
-__metaclass__ = type
 __all__ = [
     "ClientErrorView",
     "expose",
diff --git a/src/lazr/restful/example/base/filemanager.py b/src/lazr/restful/example/base/filemanager.py
index fccb0fc..781bf88 100644
--- a/src/lazr/restful/example/base/filemanager.py
+++ b/src/lazr/restful/example/base/filemanager.py
@@ -2,9 +2,6 @@
 
 """The file manager for the LAZR example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = ["FileManager", "ManagedFileResource"]
 
 import datetime
diff --git a/src/lazr/restful/example/base/interfaces.py b/src/lazr/restful/example/base/interfaces.py
index b6d7d85..c315cea 100644
--- a/src/lazr/restful/example/base/interfaces.py
+++ b/src/lazr/restful/example/base/interfaces.py
@@ -3,9 +3,6 @@
 
 """Interface objects for the LAZR example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "AlreadyNew",
     "Cuisine",
@@ -65,7 +62,7 @@ class WhitespaceStrippingTextLine(TextLine):
         """Strip whitespace before setting."""
         if value is not None:
             value = value.strip()
-        super(WhitespaceStrippingTextLine, self).set(object, value)
+        super().set(object, value)
 
 
 class Cuisine(EnumeratedType):
@@ -75,7 +72,7 @@ class Cuisine(EnumeratedType):
     VEGETARIAN = Item("Vegetarian", "Vegetarian cooking")
     AMERICAN = Item("American", "Traditional American cooking")
     DESSERT = Item("Dessert", "Desserts")
-    FRANCAISE = Item(u"Fran\xe7aise", u"Cuisine fran\xe7aise")
+    FRANCAISE = Item("Fran\xe7aise", "Cuisine fran\xe7aise")
 
 
 class IHasGet(Interface):
@@ -89,10 +86,10 @@ class IHasGet(Interface):
 class IDish(ILocation):
     """A dish, annotated for export to the web service."""
 
-    name = exported(TextLine(title=u"Name", required=True))
+    name = exported(TextLine(title="Name", required=True))
     recipes = exported(
         CollectionField(
-            title=u"Recipes in this cookbook",
+            title="Recipes in this cookbook",
             value_type=Reference(schema=Interface),
         )
     )
@@ -105,17 +102,17 @@ class IDish(ILocation):
 class IRecipe(ILocation):
     """A recipe, annotated for export to the web service."""
 
-    id = exported(Int(title=u"Unique ID", required=True))
-    dish = exported(Reference(title=u"Dish", schema=IDish))
-    cookbook = exported(Reference(title=u"Cookbook", schema=Interface))
+    id = exported(Int(title="Unique ID", required=True))
+    dish = exported(Reference(title="Dish", schema=IDish))
+    cookbook = exported(Reference(title="Cookbook", schema=Interface))
     instructions = exported(
-        Text(title=u"How to prepare the recipe", required=True)
+        Text(title="How to prepare the recipe", required=True)
     )
     private = exported(
-        Bool(title=u"Whether the public can see this recipe.", default=False)
+        Bool(title="Whether the public can see this recipe.", default=False)
     )
     prepared_image = exported(
-        Bytes(0, 5000, title=u"An image of the prepared dish.", readonly=True)
+        Bytes(0, 5000, title="An image of the prepared dish.", readonly=True)
     )
 
     @export_destructor_operation()
@@ -127,55 +124,53 @@ class IRecipe(ILocation):
 class ICookbook(IHasGet, ILocation):
     """A cookbook, annotated for export to the web service."""
 
-    name = exported(TextLine(title=u"Name", required=True))
+    name = exported(TextLine(title="Name", required=True))
     copyright_date = exported(
         Date(
-            title=u"Copyright Date",
-            description=u"The copyright date for this work.",
+            title="Copyright Date",
+            description="The copyright date for this work.",
         ),
         readonly=True,
     )
     description = exported(
-        WhitespaceStrippingTextLine(title=u"Description", required=False)
+        WhitespaceStrippingTextLine(title="Description", required=False)
     )
     revision_number = exported(
         Int(
-            title=u"A record of the number of times "
+            title="A record of the number of times "
             "this cookbook has been modified."
         )
     )
     confirmed = exported(
         Bool(
-            title=u"Whether this information has been confirmed", default=False
+            title="Whether this information has been confirmed", default=False
         )
     )
     cuisine = exported(
         Choice(
-            vocabulary=Cuisine, title=u"Cuisine", required=False, default=None
+            vocabulary=Cuisine, title="Cuisine", required=False, default=None
         )
     )
     last_printing = exported(
         Date(
-            title=u"Last printing",
-            description=u"The date of this work's most recent printing.",
+            title="Last printing",
+            description="The date of this work's most recent printing.",
         )
     )
     # Don't try this at home! Float is a bad choice for a 'price'
     # field because it's imprecise. Decimal is a better choice. But
     # this is just an example and we need a Float field, so...
-    price = exported(Float(title=u"Retail price of the cookbook"))
+    price = exported(Float(title="Retail price of the cookbook"))
     recipes = exported(
         CollectionField(
-            title=u"Recipes in this cookbook",
+            title="Recipes in this cookbook",
             value_type=Reference(schema=IRecipe),
         )
     )
-    cover = exported(
-        Bytes(0, 5000, title=u"An image of the cookbook's cover.")
-    )
+    cover = exported(Bytes(0, 5000, title="An image of the cookbook's cover."))
 
     @operation_parameters(
-        search=TextLine(title=u"String to search for in recipe name.")
+        search=TextLine(title="String to search for in recipe name.")
     )
     @operation_returns_collection_of(IRecipe)
     @export_read_operation()
@@ -183,7 +178,7 @@ class ICookbook(IHasGet, ILocation):
         """Search for recipes in this cookbook."""
 
     @operation_parameters(
-        dish=Reference(title=u"Dish to search for.", schema=IDish)
+        dish=Reference(title="Dish to search for.", schema=IDish)
     )
     @operation_returns_entry(IRecipe)
     @export_read_operation()
@@ -197,7 +192,7 @@ class ICookbook(IHasGet, ILocation):
     def removeRecipe(recipe):
         """Remove one of this cookbook's recipes."""
 
-    @operation_parameters(cover=Bytes(title=u"New cover"))
+    @operation_parameters(cover=Bytes(title="New cover"))
     @export_write_operation()
     def replace_cover(cover):
         """Replace the cookbook's cover."""
@@ -231,9 +226,9 @@ class ICookbookSet(IHasGet):
         """Return the list of cookbooks."""
 
     @operation_parameters(
-        search=TextLine(title=u"String to search for in recipe name."),
+        search=TextLine(title="String to search for in recipe name."),
         vegetarian=Bool(
-            title=u"Whether or not to limit the search to "
+            title="Whether or not to limit the search to "
             "vegetarian cookbooks.",
             default=False,
         ),
@@ -245,7 +240,7 @@ class ICookbookSet(IHasGet):
 
     @operation_parameters(
         cuisine=Choice(
-            vocabulary=Cuisine, title=u"Cuisine to search for in recipe name."
+            vocabulary=Cuisine, title="Cuisine to search for in recipe name."
         )
     )
     @operation_returns_collection_of(ICookbook)
diff --git a/src/lazr/restful/example/base/root.py b/src/lazr/restful/example/base/root.py
index 424c971..85771b7 100644
--- a/src/lazr/restful/example/base/root.py
+++ b/src/lazr/restful/example/base/root.py
@@ -2,9 +2,6 @@
 
 """Data model objects for the LAZR example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "Cookbook",
     "CookbookServiceRootResource",
@@ -382,22 +379,22 @@ def year(year):
 
 
 C1 = Cookbook(
-    u"Mastering the Art of French Cooking", "", Cuisine.FRANCAISE, year(1961)
+    "Mastering the Art of French Cooking", "", Cuisine.FRANCAISE, year(1961)
 )
-C2 = Cookbook(u"The Joy of Cooking", "", Cuisine.GENERAL, year(1995), price=20)
+C2 = Cookbook("The Joy of Cooking", "", Cuisine.GENERAL, year(1995), price=20)
 C3 = Cookbook(
-    u"James Beard's American Cookery", "", Cuisine.AMERICAN, year(1972)
+    "James Beard's American Cookery", "", Cuisine.AMERICAN, year(1972)
 )
-C4 = Cookbook(u"Everyday Greens", "", Cuisine.VEGETARIAN, year(2003))
-C5 = Cookbook(u"I'm Just Here For The Food", "", Cuisine.GENERAL, year(2002))
-C6 = Cookbook(u"Cooking Without Recipes", "", Cuisine.GENERAL, year(1959))
-C7 = Cookbook(u"Construsions un repas", "", Cuisine.FRANCAISE, year(2007))
+C4 = Cookbook("Everyday Greens", "", Cuisine.VEGETARIAN, year(2003))
+C5 = Cookbook("I'm Just Here For The Food", "", Cuisine.GENERAL, year(2002))
+C6 = Cookbook("Cooking Without Recipes", "", Cuisine.GENERAL, year(1959))
+C7 = Cookbook("Construsions un repas", "", Cuisine.FRANCAISE, year(2007))
 COOKBOOKS = [C1, C2, C3, C4, C5, C6, C7]
 
 D1 = Dish("Roast chicken")
-C1_D1 = Recipe(1, C1, D1, u"You can always judge...")
-C2_D1 = Recipe(2, C2, D1, u"Draw, singe, stuff, and truss...")
-C3_D1 = Recipe(3, C3, D1, u"A perfectly roasted chicken is...")
+C1_D1 = Recipe(1, C1, D1, "You can always judge...")
+C2_D1 = Recipe(2, C2, D1, "Draw, singe, stuff, and truss...")
+C3_D1 = Recipe(3, C3, D1, "A perfectly roasted chicken is...")
 
 D2 = Dish("Baked beans")
 C2_D2 = Recipe(4, C2, D2, "Preheat oven to...")
diff --git a/src/lazr/restful/example/base/security.py b/src/lazr/restful/example/base/security.py
index bbb5165..0f33cb0 100644
--- a/src/lazr/restful/example/base/security.py
+++ b/src/lazr/restful/example/base/security.py
@@ -2,9 +2,6 @@
 
 """A simple security policy for the LAZR example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "CookbookWebServiceSecurityPolicy",
 ]
diff --git a/src/lazr/restful/example/base/subscribers.py b/src/lazr/restful/example/base/subscribers.py
index 68ff062..fa6f973 100644
--- a/src/lazr/restful/example/base/subscribers.py
+++ b/src/lazr/restful/example/base/subscribers.py
@@ -2,9 +2,6 @@
 
 """Event listeners for the example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = ["update_cookbook_revision_number"]
 
 import grokcore.component
diff --git a/src/lazr/restful/example/base/tests/test_integration.py b/src/lazr/restful/example/base/tests/test_integration.py
index 99b987f..f0bbbb1 100644
--- a/src/lazr/restful/example/base/tests/test_integration.py
+++ b/src/lazr/restful/example/base/tests/test_integration.py
@@ -2,9 +2,6 @@
 
 """Test harness for LAZR doctests."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 import os
@@ -58,16 +55,11 @@ def load_tests(loader, tests, pattern):
         for name in os.listdir(os.path.dirname(__file__))
         if name.endswith(".txt")
     )
-    globs = {
-        "absolute_import": absolute_import,
-        "print_function": print_function,
-    }
     suite = doctest.DocFileSuite(
         *doctest_files,
         optionflags=DOCTEST_FLAGS,
-        globs=globs,
         encoding="UTF-8",
-        checker=checker
+        checker=checker,
     )
     suite.layer = WSGILayer
     tests.addTest(suite)
diff --git a/src/lazr/restful/example/base/traversal.py b/src/lazr/restful/example/base/traversal.py
index 4b06202..4ae07a9 100644
--- a/src/lazr/restful/example/base/traversal.py
+++ b/src/lazr/restful/example/base/traversal.py
@@ -2,9 +2,6 @@
 
 """Traversal rules for the LAZR example web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "BelowRootAbsoluteURL",
     "CookbookSetTraverse",
@@ -99,6 +96,4 @@ class CookbookSetTraverse(TraverseWithGet):
             url = absoluteURL(self.context.featured, request) + "{invalid}"
             return RedirectResource(url, request)
         else:
-            return super(CookbookSetTraverse, self).publishTraverse(
-                request, name
-            )
+            return super().publishTraverse(request, name)
diff --git a/src/lazr/restful/example/base_extended/comments.py b/src/lazr/restful/example/base_extended/comments.py
index 8db2763..5973204 100644
--- a/src/lazr/restful/example/base_extended/comments.py
+++ b/src/lazr/restful/example/base_extended/comments.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function
-
 from zope.component import adapter
 from zope.interface import implementer, Interface
 from zope.schema import List, Text
@@ -15,7 +13,7 @@ from lazr.restful.declarations import (
 @exported_as_webservice_entry(contributes_to=[IRecipe])
 class IHasComments(Interface):
     comments = exported(
-        List(title=u"Comments made by users", value_type=Text())
+        List(title="Comments made by users", value_type=Text())
     )
 
 
diff --git a/src/lazr/restful/example/base_extended/tests/test_integration.py b/src/lazr/restful/example/base_extended/tests/test_integration.py
index e5b0021..866c905 100644
--- a/src/lazr/restful/example/base_extended/tests/test_integration.py
+++ b/src/lazr/restful/example/base_extended/tests/test_integration.py
@@ -2,9 +2,6 @@
 
 """Test harness for LAZR doctests."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 import os
@@ -46,12 +43,8 @@ wsgi_intercept_layer(WSGILayer)
 def load_tests(loader, tests, pattern):
     """See `zope.testing.testrunner`."""
     doctest_files = ["../README.txt"]
-    globs = {
-        "absolute_import": absolute_import,
-        "print_function": print_function,
-    }
     suite = doctest.DocFileSuite(
-        *doctest_files, optionflags=DOCTEST_FLAGS, globs=globs, checker=checker
+        *doctest_files, optionflags=DOCTEST_FLAGS, checker=checker
     )
     suite.layer = WSGILayer
     tests.addTest(suite)
diff --git a/src/lazr/restful/example/multiversion/resources.py b/src/lazr/restful/example/multiversion/resources.py
index 849d579..cf45690 100644
--- a/src/lazr/restful/example/multiversion/resources.py
+++ b/src/lazr/restful/example/multiversion/resources.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 __all__ = ["IKeyValuePair", "IPairSet", "KeyValuePair", "PairSet"]
 
 from zope.interface import implementer
@@ -36,14 +32,14 @@ from lazr.restful.example.wsgi.resources import (
 # define them separately.
 @exported_as_webservice_entry()
 class IKeyValuePair(ILocation):
-    key = exported(Text(title=u"The key"))
-    value = exported(Text(title=u"The value"))
+    key = exported(Text(title="The key"))
+    value = exported(Text(title="The value"))
     a_comment = exported(
-        Text(title=u"A comment on this key-value pair.", readonly=True),
+        Text(title="A comment on this key-value pair.", readonly=True),
         ("1.0", dict(exported=True, exported_as="comment")),
     )
     deleted = exported(
-        Bool(title=u"Whether this key-value pair has been " "deleted"),
+        Bool(title="Whether this key-value pair has been " "deleted"),
         ("3.0", dict(exported=True)),
         exported=False,
     )
@@ -117,7 +113,7 @@ class PairSet(BasicPairSet):
 @implementer(IKeyValuePair)
 class KeyValuePair(BasicKeyValuePair):
     def __init__(self, pairset, key, value):
-        super(KeyValuePair, self).__init__(pairset, key, value)
+        super().__init__(pairset, key, value)
         self.a_comment = ""
         self.deleted = False
 
diff --git a/src/lazr/restful/example/multiversion/root.py b/src/lazr/restful/example/multiversion/root.py
index 2391d4b..c611cda 100644
--- a/src/lazr/restful/example/multiversion/root.py
+++ b/src/lazr/restful/example/multiversion/root.py
@@ -1,8 +1,5 @@
 """The RESTful service root."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "BelowRootAbsoluteURL",
     "RootAbsoluteURL",
diff --git a/src/lazr/restful/example/multiversion/tests/test_integration.py b/src/lazr/restful/example/multiversion/tests/test_integration.py
index 92772a4..ee04982 100644
--- a/src/lazr/restful/example/multiversion/tests/test_integration.py
+++ b/src/lazr/restful/example/multiversion/tests/test_integration.py
@@ -2,9 +2,6 @@
 
 """Test harness for doctests for lazr.restful multiversion example service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 import os
@@ -59,12 +56,8 @@ def load_tests(loader, tests, pattern):
         for name in os.listdir(os.path.dirname(__file__))
         if name.endswith(".txt")
     )
-    globs = {
-        "absolute_import": absolute_import,
-        "print_function": print_function,
-    }
     suite = doctest.DocFileSuite(
-        *doctest_files, optionflags=DOCTEST_FLAGS, globs=globs, checker=checker
+        *doctest_files, optionflags=DOCTEST_FLAGS, checker=checker
     )
     suite.layer = WSGILayer
     tests.addTest(suite)
diff --git a/src/lazr/restful/example/wsgi/resources.py b/src/lazr/restful/example/wsgi/resources.py
index ad42f66..1ae11fc 100644
--- a/src/lazr/restful/example/wsgi/resources.py
+++ b/src/lazr/restful/example/wsgi/resources.py
@@ -1,7 +1,3 @@
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 __all__ = ["IKeyValuePair", "IPairSet", "KeyValuePair", "PairSet"]
 
 from zope.component import getUtility
@@ -21,8 +17,8 @@ from lazr.restful.simple import TraverseWithGet
 
 @exported_as_webservice_entry()
 class IKeyValuePair(ILocation):
-    key = exported(Text(title=u"The key"))
-    value = exported(Text(title=u"The value"))
+    key = exported(Text(title="The key"))
+    value = exported(Text(title="The value"))
 
 
 @exported_as_webservice_collection(IKeyValuePair)
@@ -36,7 +32,7 @@ class IPairSet(ILocation):
 
 
 @implementer(IKeyValuePair, ILocation)
-class KeyValuePair(object):
+class KeyValuePair:
     """An object representing a key-value pair"""
 
     def __init__(self, set, key, value):
diff --git a/src/lazr/restful/example/wsgi/root.py b/src/lazr/restful/example/wsgi/root.py
index efd246d..a870d0b 100644
--- a/src/lazr/restful/example/wsgi/root.py
+++ b/src/lazr/restful/example/wsgi/root.py
@@ -1,8 +1,5 @@
 """The RESTful service root."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "BelowRootAbsoluteURL",
     "RootAbsoluteURL",
diff --git a/src/lazr/restful/example/wsgi/run.py b/src/lazr/restful/example/wsgi/run.py
index b49b188..ff0dedc 100644
--- a/src/lazr/restful/example/wsgi/run.py
+++ b/src/lazr/restful/example/wsgi/run.py
@@ -1,7 +1,5 @@
 #!/usr/bin/python
 
-from __future__ import absolute_import, print_function
-
 from lazr.restful.wsgi import WSGIApplication
 
 if __name__ == "__main__":
diff --git a/src/lazr/restful/example/wsgi/tests/test_integration.py b/src/lazr/restful/example/wsgi/tests/test_integration.py
index f8f5583..cc02ba7 100644
--- a/src/lazr/restful/example/wsgi/tests/test_integration.py
+++ b/src/lazr/restful/example/wsgi/tests/test_integration.py
@@ -2,9 +2,6 @@
 
 """Test harness for doctests for lazr.restful example WSGI service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 import os
@@ -57,12 +54,8 @@ def load_tests(loader, tests, pattern):
         for name in os.listdir(os.path.dirname(__file__))
         if name.endswith(".txt")
     )
-    globs = {
-        "absolute_import": absolute_import,
-        "print_function": print_function,
-    }
     suite = doctest.DocFileSuite(
-        *doctest_files, optionflags=DOCTEST_FLAGS, globs=globs, checker=checker
+        *doctest_files, optionflags=DOCTEST_FLAGS, checker=checker
     )
     suite.layer = WSGILayer
     tests.addTest(suite)
diff --git a/src/lazr/restful/fields.py b/src/lazr/restful/fields.py
index a9e9756..4699769 100644
--- a/src/lazr/restful/fields.py
+++ b/src/lazr/restful/fields.py
@@ -2,9 +2,6 @@
 
 """LAZR zope.schema.IField implementation."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "CollectionField",
     "Reference",
@@ -39,7 +36,7 @@ class CollectionField(AbstractCollection):
         are managed through a dedicated API.
         """
         kwargs.setdefault("readonly", True)
-        super(CollectionField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
 
 @implementer(IReference)
@@ -75,4 +72,4 @@ class ReferenceChoice(Choice):
         """
         schema = kwargs.pop("schema", IObject)
         self.schema = schema
-        super(ReferenceChoice, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
diff --git a/src/lazr/restful/frameworks/django.py b/src/lazr/restful/frameworks/django.py
index a1d09c2..a7ae447 100644
--- a/src/lazr/restful/frameworks/django.py
+++ b/src/lazr/restful/frameworks/django.py
@@ -2,7 +2,6 @@
 
 """Helpers for publishing Django model objects in lazr.restful services."""
 
-__metaclass__ = type
 __all__ = [
     "DjangoLocation",
     "DjangoWebServiceConfiguration",
@@ -102,7 +101,7 @@ class DjangoAbsoluteURL(AbsoluteURL):
 
 
 @implementer(ILocation)
-class DjangoLocation(object):
+class DjangoLocation:
     """Adapts Django model objects to ILocation.
 
     See `IDjangoLocation` for why Django model objects can't implement
@@ -125,7 +124,7 @@ grokcore.component.global_adapter(DjangoLocation, IDjangoLocation, ILocation)
 
 
 @implementer(IFiniteSequence)
-class ManagerSequencer(object):
+class ManagerSequencer:
     """Makes a Django manager object usable with lazr.batchnavigator.
 
     IFiniteSequence requires that we implement __len__, and either
diff --git a/src/lazr/restful/interface.py b/src/lazr/restful/interface.py
index a69cf98..e63dcf1 100644
--- a/src/lazr/restful/interface.py
+++ b/src/lazr/restful/interface.py
@@ -2,9 +2,6 @@
 
 """Helpers for working with Zope interface."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = ["copy_attribute", "copy_field", "use_template"]
 
 import sys
diff --git a/src/lazr/restful/interfaces/__init__.py b/src/lazr/restful/interfaces/__init__.py
index b0d1c27..8c7ea66 100644
--- a/src/lazr/restful/interfaces/__init__.py
+++ b/src/lazr/restful/interfaces/__init__.py
@@ -17,8 +17,6 @@
 
 # pylint: disable-msg=W0401
 
-from __future__ import absolute_import, print_function
-
 __version__ = 1.0
 
 # Re-export in such a way that __version__ can still be imported if
diff --git a/src/lazr/restful/interfaces/_fields.py b/src/lazr/restful/interfaces/_fields.py
index d48a87d..36a15c1 100644
--- a/src/lazr/restful/interfaces/_fields.py
+++ b/src/lazr/restful/interfaces/_fields.py
@@ -16,9 +16,6 @@
 
 """Interfaces for LAZR zope.schema fields."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "ICollectionField",
     "IReference",
diff --git a/src/lazr/restful/interfaces/_rest.py b/src/lazr/restful/interfaces/_rest.py
index 9632dc6..8b92c74 100644
--- a/src/lazr/restful/interfaces/_rest.py
+++ b/src/lazr/restful/interfaces/_rest.py
@@ -18,9 +18,6 @@
 # Pylint doesn't grok zope interfaces.
 # pylint: disable-msg=E0211,E0213
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "IByteStorage",
     "IByteStorageResource",
@@ -479,8 +476,8 @@ class IWebServiceConfiguration(Interface):
     caching_policy = List(
         value_type=Int(),
         default=[7 * 24 * HOUR, 1 * HOUR],
-        title=u"The web service caching policy.",
-        description=u"""A list of two numbers, each to be used in the
+        title="The web service caching policy.",
+        description="""A list of two numbers, each to be used in the
         'max-age' field of the Cache-Control header. The first number is
         used when serving the service root for any web service version
         except the latest one. The second number is used when serving the
@@ -489,32 +486,32 @@ class IWebServiceConfiguration(Interface):
     )
 
     enable_server_side_representation_cache = Bool(
-        title=u"Enable the server-side representation cache.",
+        title="Enable the server-side representation cache.",
         default=True,
-        description=u"""If this is false, the server-side representation
+        description="""If this is false, the server-side representation
         cache will not be used, even if one is registered.""",
     )
 
     service_description = TextLine(
-        title=u"Service description",
-        description=u"""A human-readable description of the web service.
+        title="Service description",
+        description="""A human-readable description of the web service.
 
         The description may contain HTML, but if it does, it must be a
         valid XHTML fragment.
         """,
-        default=u"",
+        default="",
     )
 
     view_permission = TextLine(
-        title=u"View permission",
-        default=u"zope.View",
-        description=u"The permission to use when checking object visibility.",
+        title="View permission",
+        default="zope.View",
+        description="The permission to use when checking object visibility.",
     )
 
     path_override = TextLine(
-        title=u"Web service path override",
-        default=u"api",
-        description=u"The path component for Ajax clients to use when making "
+        title="Web service path override",
+        default="api",
+        description="The path component for Ajax clients to use when making "
         "HTTP requests to the web service from their current virtual host. "
         "The use of this path component (/api/foo instead of /foo) will "
         "ensure that the request is processed as a web service request "
@@ -522,29 +519,29 @@ class IWebServiceConfiguration(Interface):
     )
 
     use_https = Bool(
-        title=u"Web service is secured",
+        title="Web service is secured",
         default=True,
-        description=u"Whether or not requests to the web service are secured "
+        description="Whether or not requests to the web service are secured "
         "through SSL.",
     )
 
     hostname = TextLine(
-        title=u"The hostname to be used in generated URLs.",
-        description=u"You only need to specify this if you're using the "
+        title="The hostname to be used in generated URLs.",
+        description="You only need to specify this if you're using the "
         "RootResourceAbsoluteURL class from lazr.restful.simple. This is "
         "the hostname of the lazr.restful application.",
     )
 
     port = Int(
-        title=u"The TCP port on which the web service is running.",
-        description=u"Used in generated URLs.",
+        title="The TCP port on which the web service is running.",
+        description="Used in generated URLs.",
         default=0,
     )
 
     service_root_uri_prefix = TextLine(
-        title=u"Any URL prefix necessary for the service root.",
-        default=u"",
-        description=u"If your web service is not located at the root of "
+        title="Any URL prefix necessary for the service root.",
+        default="",
+        description="If your web service is not located at the root of "
         "its domain (for instance, it's rooted at "
         "http://foo.com/web-service/ instead of http://api.foo/com/, "
         "put the URL prefix here. (In the example case, the URL prefix "
@@ -554,8 +551,8 @@ class IWebServiceConfiguration(Interface):
     active_versions = List(
         value_type=TextLine(),
         default=[],
-        title=u"The active versions of the web service.",
-        description=u"""A list of names of active versions of this
+        title="The active versions of the web service.",
+        description="""A list of names of active versions of this
         web service. They might be version numbers, names such as
         "beta", or the date a particular version was finalized.
 
@@ -571,8 +568,8 @@ class IWebServiceConfiguration(Interface):
     version_descriptions = Dict(
         key_type=TextLine(),
         value_type=Text(),
-        title=u"Human-readable descriptions of the web service versions.",
-        description=u"""A dictionary mapping version names to
+        title="Human-readable descriptions of the web service versions.",
+        description="""A dictionary mapping version names to
         human-readable descriptions. The descriptions should describe
         what distinguishes this version from other versions, and
         mention if/when the version will be removed.
@@ -585,7 +582,7 @@ class IWebServiceConfiguration(Interface):
 
     require_explicit_versions = Bool(
         default=False,
-        description=u"""If true, each exported field and named
+        description="""If true, each exported field and named
         operation must explicitly declare the first version in which
         it appears. If false, fields and operations are published in
         all versions.""",
@@ -593,7 +590,7 @@ class IWebServiceConfiguration(Interface):
 
     last_version_with_mutator_named_operations = TextLine(
         default=None,
-        description=u"""In earlier versions of lazr.restful, mutator methods
+        description="""In earlier versions of lazr.restful, mutator methods
         were also published as named operations. This redundant
         behavior is no longer enabled by default, but this setting
         allows for backwards compatibility.
@@ -606,48 +603,48 @@ class IWebServiceConfiguration(Interface):
 
     first_version_with_total_size_link = TextLine(
         default=None,
-        description=u"""In earlier versions of lazr.restful collections
+        description="""In earlier versions of lazr.restful collections
         included a total_size field, now they include a total_size_link
         instead. Setting this value determines in which version the new
         behavior takes effect.""",
     )
 
     code_revision = TextLine(
-        default=u"",
-        description=u"""A string designating the current revision
+        default="",
+        description="""A string designating the current revision
         number of the code running the webservice. This may be a
         revision number from version control, or a hand-chosen version
         number.""",
     )
 
     show_tracebacks = Bool(
-        title=u"Show tracebacks to end-users",
+        title="Show tracebacks to end-users",
         default=True,
-        description=u"Whether or not to show tracebacks in an HTTP response "
+        description="Whether or not to show tracebacks in an HTTP response "
         "for a request that raised an exception.",
     )
 
     default_batch_size = Int(
-        title=u"The default batch size to use when serving a collection",
+        title="The default batch size to use when serving a collection",
         default=50,
-        description=u"When the client requests a collection and doesn't "
+        description="When the client requests a collection and doesn't "
         "specify how many entries they want, this many entries will be "
         "served them in the first page.",
     )
 
     max_batch_size = Int(
-        title=u"The maximum batch size",
+        title="The maximum batch size",
         default=300,
-        description=u"When the client requests a batch of entries from "
+        description="When the client requests a batch of entries from "
         "a collection, they will not be allowed to request more entries "
         "in the batch than this.",
     )
 
     compensate_for_mod_compress_etag_modification = Bool(
-        title=u"Accept incoming ETags that appear to have been modified "
+        title="Accept incoming ETags that appear to have been modified "
         "in transit by Apache's mod_compress.",
         default=False,
-        description=u"""When mod_compress compresses an outgoing
+        description="""When mod_compress compresses an outgoing
         representation, it (correctly) modifies the ETag. But when
         that ETag comes back in on a conditional GET or PUT request,
         mod_compress does _not_ transparently remove the modification,
diff --git a/src/lazr/restful/jsoncache.py b/src/lazr/restful/jsoncache.py
index 5c217c2..02349c3 100644
--- a/src/lazr/restful/jsoncache.py
+++ b/src/lazr/restful/jsoncache.py
@@ -2,10 +2,6 @@
 #
 """A class for storing resources where they can be seen by a template."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 __all__ = ["JSONRequestCache"]
 
 from lazr.restful.interfaces import IJSONRequestCache, LAZR_WEBSERVICE_NS
diff --git a/src/lazr/restful/marshallers.py b/src/lazr/restful/marshallers.py
index bec584a..3439106 100644
--- a/src/lazr/restful/marshallers.py
+++ b/src/lazr/restful/marshallers.py
@@ -2,9 +2,6 @@
 
 """Marshallers for fields used in HTTP resources."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "AbstractCollectionFieldMarshaller",
     "BoolFieldMarshaller",
@@ -31,7 +28,6 @@ import re
 
 import pytz
 import simplejson
-import six
 from six.moves.urllib.parse import unquote
 
 from zope.datetime import (
@@ -92,9 +88,9 @@ class URLDereferencingMixin:
             request_host = full_request_host
             request_port = default_port
 
-        if not isinstance(url, six.string_types):
+        if not isinstance(url, str):
             raise ValueError(
-                u"got '%s', expected string: %r" % (type(url).__name__, url)
+                "got '%s', expected string: %r" % (type(url).__name__, url)
             )
         if url.startswith("/"):
             # It's a relative URI. Resolve it relative to the root of this
@@ -145,9 +141,9 @@ class URLDereferencingMixin:
             resource = self.dereference_url(url)
         except NotFound:
             # The URL doesn't correspond to any real object.
-            raise ValueError(u'No such object "%s".' % url)
+            raise ValueError('No such object "%s".' % url)
         except InvalidURIError:
-            raise ValueError(u'"%s" is not a valid URI.' % url)
+            raise ValueError('"%s" is not a valid URI.' % url)
         # We looked up the URL and got the thing at the other end of
         # the URL: a resource. But internally, a resource isn't a
         # valid value for any schema field. Instead we want the object
@@ -193,8 +189,8 @@ class SimpleFieldMarshaller:
                 v = value
                 if isinstance(v, bytes):
                     v = v.decode("utf8")  # assume utf8
-                elif not isinstance(v, six.text_type):
-                    v = six.text_type(v)
+                elif not isinstance(v, str):
+                    v = str(v)
                 value = simplejson.loads(v)
             except (ValueError, TypeError):
                 # Pass the value as is. This saves client from having to encode
@@ -225,7 +221,7 @@ class SimpleFieldMarshaller:
                 else:
                     expected_name = self._type.__name__
                 raise ValueError(
-                    u"got '%s', expected %s: %r"
+                    "got '%s', expected %s: %r"
                     % (type(value).__name__, expected_name, value)
                 )
         return value
@@ -275,9 +271,7 @@ class FloatFieldMarshaller(SimpleFieldMarshaller):
 
         Converts the value to a float.
         """
-        return float(
-            super(FloatFieldMarshaller, self)._marshall_from_json_data(value)
-        )
+        return float(super()._marshall_from_json_data(value))
 
 
 class BytesFieldMarshaller(SimpleFieldMarshaller):
@@ -319,7 +313,7 @@ class BytesFieldMarshaller(SimpleFieldMarshaller):
         if safe_hasattr(value, "seek"):
             value.seek(0)
             value = value.read()
-        elif not isinstance(value, (bytes, six.text_type)):
+        elif not isinstance(value, (bytes, str)):
             value = str(value).encode("UTF-8")
         else:
             # Leave string conversion to _marshall_from_json_data.
@@ -331,17 +325,15 @@ class BytesFieldMarshaller(SimpleFieldMarshaller):
 
         Convert all strings to byte strings.
         """
-        if isinstance(value, six.text_type):
+        if isinstance(value, str):
             value = value.encode("utf-8")
-        return super(BytesFieldMarshaller, self)._marshall_from_json_data(
-            value
-        )
+        return super()._marshall_from_json_data(value)
 
 
 class TextFieldMarshaller(SimpleFieldMarshaller):
     """FieldMarshaller for IText fields."""
 
-    _type = six.text_type
+    _type = str
     _type_error_message = "not a unicode string: %r"
 
     def _marshall_from_request(self, value):
@@ -349,12 +341,12 @@ class TextFieldMarshaller(SimpleFieldMarshaller):
 
         Converts the value to unicode.
         """
-        value = six.text_type(value)
+        value = str(value)
         # multipart/form-data encoding of text fields is required (RFC 2046
         # section 4.1.1) to use CRLF for line breaks.  Normalize to
         # Unix-style LF.
         value = re.sub(r"\r\n?", "\n", value)
-        return super(TextFieldMarshaller, self)._marshall_from_request(value)
+        return super()._marshall_from_request(value)
 
 
 class FixedVocabularyFieldMarshaller(SimpleFieldMarshaller):
@@ -369,7 +361,7 @@ class FixedVocabularyFieldMarshaller(SimpleFieldMarshaller):
             part of a multiadapter lookup of the appropriate
             marshaller.
         """
-        super(FixedVocabularyFieldMarshaller, self).__init__(field, request)
+        super().__init__(field, request)
 
     def unmarshall_to_closeup(self, entry, value):
         """Describe all values, not just the selected value."""
@@ -386,9 +378,7 @@ class TokenizedVocabularyFieldMarshaller(FixedVocabularyFieldMarshaller):
     """A marshaller that looks up value using a token in a vocabulary."""
 
     def __init__(self, field, request, vocabulary):
-        super(TokenizedVocabularyFieldMarshaller, self).__init__(
-            field, request, vocabulary
-        )
+        super().__init__(field, request, vocabulary)
 
     def _marshall_from_json_data(self, value):
         """See `SimpleFieldMarshaller`.
@@ -396,11 +386,9 @@ class TokenizedVocabularyFieldMarshaller(FixedVocabularyFieldMarshaller):
         Looks up the value as a token in the vocabulary.
         """
         try:
-            return self.field.vocabulary.getTermByToken(
-                six.text_type(value)
-            ).value
+            return self.field.vocabulary.getTermByToken(str(value)).value
         except LookupError:
-            raise ValueError(u"%r isn't a valid token" % value)
+            raise ValueError("%r isn't a valid token" % value)
 
 
 class DateTimeFieldMarshaller(SimpleFieldMarshaller):
@@ -454,7 +442,7 @@ class DateFieldMarshaller(DateTimeFieldMarshaller):
 
     def _marshall_from_json_data(self, value):
         """Parse the value as a datetime.date object."""
-        super_class = super(DateFieldMarshaller, self)
+        super_class = super()
         date_time = super_class._marshall_from_json_data(value)
         return date_time.date()
 
@@ -475,7 +463,7 @@ class AbstractCollectionFieldMarshaller(SimpleFieldMarshaller):
 
         This also looks for the appropriate marshaller for value_type.
         """
-        super(AbstractCollectionFieldMarshaller, self).__init__(field, request)
+        super().__init__(field, request)
         self.value_marshaller = getMultiAdapter(
             (field.value_type or Field(), request), IFieldMarshaller
         )
@@ -486,9 +474,7 @@ class AbstractCollectionFieldMarshaller(SimpleFieldMarshaller):
         Marshall every elements of the list using the appropriate
         marshaller.
         """
-        value = super(
-            AbstractCollectionFieldMarshaller, self
-        )._marshall_from_json_data(value)
+        value = super()._marshall_from_json_data(value)
 
         # In AbstractCollection subclasses, _type contains the type object,
         # which can be used as a factory.
@@ -556,7 +542,7 @@ class DictFieldMarshaller(SimpleFieldMarshaller):
         value_type. If key_type or value_type are not specified, the default
         field marshaller is used.
         """
-        super(DictFieldMarshaller, self).__init__(field, request)
+        super().__init__(field, request)
         self.key_marshaller = getMultiAdapter(
             (field.key_type or Field(), request), IFieldMarshaller
         )
@@ -582,7 +568,7 @@ class DictFieldMarshaller(SimpleFieldMarshaller):
             try:
                 value = dict(nv.split(",", 2) for nv in value)
             except ValueError:
-                raise ValueError(u"got '%s', list of name,value pairs" % value)
+                raise ValueError("got '%s', list of name,value pairs" % value)
         return {
             self.key_marshaller.marshall_from_json_data(
                 key
@@ -602,9 +588,7 @@ class DictFieldMarshaller(SimpleFieldMarshaller):
         if isinstance(value, list):
             value = dict(value)
         # Call super to check for errors and raise a ValueError if necessary.
-        value = super(DictFieldMarshaller, self)._marshall_from_json_data(
-            value
-        )
+        value = super()._marshall_from_json_data(value)
         return {
             self.key_marshaller.marshall_from_json_data(
                 key
@@ -671,9 +655,7 @@ class SimpleVocabularyLookupFieldMarshaller(FixedVocabularyFieldMarshaller):
 
     def __init__(self, field, request, vocabulary):
         """Initialize the marshaller with the vocabulary it'll use."""
-        super(SimpleVocabularyLookupFieldMarshaller, self).__init__(
-            field, request, vocabulary
-        )
+        super().__init__(field, request, vocabulary)
         self.vocabulary = vocabulary
 
     def _marshall_from_json_data(self, value):
@@ -684,7 +666,7 @@ class SimpleVocabularyLookupFieldMarshaller(FixedVocabularyFieldMarshaller):
                 return item
             valid_titles.append(item.title)
         raise ValueError(
-            u'Invalid value "%s". Acceptable values are: %s'
+            'Invalid value "%s". Acceptable values are: %s'
             % (value, ", ".join(valid_titles))
         )
 
@@ -704,7 +686,7 @@ class ObjectLookupFieldMarshaller(
     """
 
     def __init__(self, field, request, vocabulary=None):
-        super(ObjectLookupFieldMarshaller, self).__init__(field, request)
+        super().__init__(field, request)
         self.vocabulary = vocabulary
 
     @property
diff --git a/src/lazr/restful/metazcml.py b/src/lazr/restful/metazcml.py
index 1fe9422..09c0274 100644
--- a/src/lazr/restful/metazcml.py
+++ b/src/lazr/restful/metazcml.py
@@ -2,9 +2,6 @@
 
 """ZCML registration directives for the LAZR webservice framework."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 
@@ -82,7 +79,7 @@ class IRegisterDirective(Interface):
     """
 
     module = GlobalObject(
-        title=u"Module which will be inspected for webservice declarations"
+        title="Module which will be inspected for webservice declarations"
     )
 
 
diff --git a/src/lazr/restful/publisher.py b/src/lazr/restful/publisher.py
index eb628a4..92b668a 100644
--- a/src/lazr/restful/publisher.py
+++ b/src/lazr/restful/publisher.py
@@ -6,9 +6,6 @@ This module defines classes that are usually needed for integration
 with the Zope publisher.
 """
 
-from __future__ import absolute_import, division, print_function
-
-__metaclass__ = type
 __all__ = [
     "browser_request_to_web_service_request",
     "WebServicePublicationMixin",
@@ -119,9 +116,7 @@ class WebServicePublicationMixin:
                 else:
                     # Falls through to our parent version.
                     pass
-        return super(WebServicePublicationMixin, self).traverseName(
-            request, ob, name
-        )
+        return super().traverseName(request, ob, name)
 
     def _traverseToByteStorage(self, request, entry, field, name):
         """Try to traverse to a byte storage resource in entry."""
@@ -223,9 +218,7 @@ class WebServicePublicationMixin:
 
     def callObject(self, request, object):
         """Help web browsers handle redirects correctly."""
-        value = super(WebServicePublicationMixin, self).callObject(
-            request, object
-        )
+        value = super().callObject(request, object)
         self._processNotifications(request)
         if request.response.getStatus() // 100 == 3:
             if IWebBrowserInitiatedRequest.providedBy(request):
@@ -263,7 +256,7 @@ class WebServicePublicationMixin:
 
 
 @implementer(IWebServiceClientRequest)
-class WebServiceRequestTraversal(object):
+class WebServiceRequestTraversal:
     """Mixin providing web-service resource wrapping in traversal.
 
     This should be mixed in the request using to the base publication used.
@@ -288,7 +281,7 @@ class WebServiceRequestTraversal(object):
         # was requested and has set the application appropriately, so
         # now we can get a good value for 'ob' and traverse it.
         ob = self.publication.getApplication(self)
-        result = super(WebServiceRequestTraversal, self).traverse(ob)
+        result = super().traverse(ob)
         return self.publication.getResource(self, result)
 
     def _removeVirtualHostTraversals(self):
diff --git a/src/lazr/restful/security.py b/src/lazr/restful/security.py
index 05d5802..f7cc532 100644
--- a/src/lazr/restful/security.py
+++ b/src/lazr/restful/security.py
@@ -2,9 +2,6 @@
 
 """Utilities for dealing with zope security."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "protect_schema",
 ]
diff --git a/src/lazr/restful/simple.py b/src/lazr/restful/simple.py
index b846e96..2c58320 100644
--- a/src/lazr/restful/simple.py
+++ b/src/lazr/restful/simple.py
@@ -1,8 +1,5 @@
 """Simple implementations of various Zope and lazr.restful interfaces."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "BaseRepresentationCache",
     "BaseWebServiceConfiguration",
@@ -20,7 +17,6 @@ __all__ = [
 
 import traceback
 
-import six
 from six.moves.urllib.parse import (
     quote,
     unquote,
@@ -63,7 +59,7 @@ from lazr.restful.utils import (
 
 
 @implementer(IPublication)
-class PublicationMixin(object):
+class PublicationMixin:
     """A very simple implementation of `IPublication`.
 
     The object passed to the constructor is returned by getApplication().
@@ -160,7 +156,7 @@ class Publication(WebServicePublicationMixin, PublicationMixin):
 
 
 @implementer(ITraverseWithGet)
-class TraverseWithGet(object):
+class TraverseWithGet:
     """An implementation of `IPublishTraverse` that uses the get() method.
 
     This is a simple traversal technique that works with any object
@@ -395,9 +391,7 @@ class MultiplePathPartAbsoluteURL:
         parts = getattr(self.context, "__path_parts__", None)
         if parts is None:
             raise TypeError(_insufficientContext)
-        if isinstance(parts, six.string_types) or not hasattr(
-            parts, "__iter__"
-        ):
+        if isinstance(parts, str) or not hasattr(parts, "__iter__"):
             raise TypeError(
                 "Expected an iterable of strings for __path_parts__."
             )
@@ -409,7 +403,7 @@ class MultiplePathPartAbsoluteURL:
 
 
 @implementer(IRepresentationCache)
-class BaseRepresentationCache(object):
+class BaseRepresentationCache:
     """A useful base class for representation caches.
 
     When an object is invalidated, all of its representations must be
diff --git a/src/lazr/restful/tales.py b/src/lazr/restful/tales.py
index 2968667..0be2185 100644
--- a/src/lazr/restful/tales.py
+++ b/src/lazr/restful/tales.py
@@ -26,10 +26,6 @@
 
 """Implementation of the ws: namespace in TALES."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 import operator
 import re
 import simplejson
@@ -370,7 +366,7 @@ class WadlEntryResourceAPI(WadlResourceAPI):
 
     def __init__(self, entry_resource):
         "Initialize with an entry resource."
-        super(WadlEntryResourceAPI, self).__init__(entry_resource)
+        super().__init__(entry_resource)
         self.entry = self.resource.entry
         self.schema = self.entry.schema
 
@@ -407,7 +403,7 @@ class WadlCollectionResourceAPI(WadlResourceAPI):
                 + quote(relationship_name)
             )
         else:
-            return super(WadlCollectionResourceAPI, self).url
+            return super().url
 
     @property
     def type_link(self):
@@ -563,9 +559,7 @@ class WadlEntryInterfaceAdapterAPI(WadlResourceAdapterAPI):
     """
 
     def __init__(self, entry_interface):
-        super(WadlEntryInterfaceAdapterAPI, self).__init__(
-            entry_interface, IEntry
-        )
+        super().__init__(entry_interface, IEntry)
         self.utility = EntryAdapterUtility.forEntryInterface(
             entry_interface, get_current_web_service_request()
         )
@@ -584,7 +578,7 @@ class WadlEntryAdapterAPI(WadlResourceAdapterAPI):
     """
 
     def __init__(self, adapter):
-        super(WadlEntryAdapterAPI, self).__init__(adapter, IEntry)
+        super().__init__(adapter, IEntry)
         self.utility = EntryAdapterUtility(adapter)
 
     @property
@@ -662,7 +656,7 @@ class WadlCollectionAdapterAPI(WadlResourceAdapterAPI):
     "Namespace for WADL functions that operate on collection adapters."
 
     def __init__(self, adapter):
-        super(WadlCollectionAdapterAPI, self).__init__(adapter, ICollection)
+        super().__init__(adapter, ICollection)
 
     @property
     def collection_type(self):
diff --git a/src/lazr/restful/testing/event.py b/src/lazr/restful/testing/event.py
index 7431413..e199790 100644
--- a/src/lazr/restful/testing/event.py
+++ b/src/lazr/restful/testing/event.py
@@ -2,10 +2,6 @@
 
 """Helper class for checking the event notifications."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 import zope.component
 
 
diff --git a/src/lazr/restful/testing/helpers.py b/src/lazr/restful/testing/helpers.py
index 46c7d90..fc9c8b1 100644
--- a/src/lazr/restful/testing/helpers.py
+++ b/src/lazr/restful/testing/helpers.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import, print_function
-
 import sys
 from types import ModuleType
 
diff --git a/src/lazr/restful/testing/tales.py b/src/lazr/restful/testing/tales.py
index ad64e0b..ce08dce 100644
--- a/src/lazr/restful/testing/tales.py
+++ b/src/lazr/restful/testing/tales.py
@@ -2,10 +2,6 @@
 
 """Helper functions for testing TALES expressions."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 __all__ = [
     "test_tales",
 ]
diff --git a/src/lazr/restful/testing/webservice.py b/src/lazr/restful/testing/webservice.py
index 9eccb04..a4405b1 100644
--- a/src/lazr/restful/testing/webservice.py
+++ b/src/lazr/restful/testing/webservice.py
@@ -2,9 +2,6 @@
 
 """Testing helpers for webservice unit tests."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "create_web_service_request",
     "StubAbsoluteURL",
@@ -141,7 +138,7 @@ class FakeResponse:
         if result is None:
             result = ""
 
-        if not isinstance(result, six.string_types):
+        if not isinstance(result, str):
             raise ValueError("only strings and None results are handled")
 
         self.result = result
@@ -200,7 +197,7 @@ def pformat_value(value):
     JSON strings are always Unicode, never bytes, so this doesn't introduce
     ambiguity.
     """
-    if isinstance(value, six.text_type):
+    if isinstance(value, str):
         value = value.encode("unicode_escape").decode("ASCII")
         if "'" in value and '"' not in value:
             return '"%s"' % value
@@ -259,7 +256,7 @@ class WebServiceApplication(Application):
     """A WSGI application for the tests."""
 
     def __init__(self, global_config, publication, **options):
-        if isinstance(publication, six.string_types):
+        if isinstance(publication, str):
             Application.__init__(self, global_config, publication, **options)
         else:
             self.publication = publication(global_config, **options)
@@ -329,7 +326,7 @@ class WebServiceCaller:
         headers=None,
         api_version=None,
     ):
-        if isinstance(path_or_url, (bytes, six.text_type)):
+        if isinstance(path_or_url, (bytes, str)):
             path_or_url = six.ensure_str(path_or_url)
         else:
             path_or_url = str(path_or_url)
@@ -468,7 +465,7 @@ class WebServiceCaller:
             if isinstance(value, io.BufferedIOBase):
                 buf.write(value.read())
             else:
-                if not isinstance(value, six.string_types):
+                if not isinstance(value, str):
                     value = simplejson.dumps(value)
                 lines = re.split(r"\r\n|\r|\n", value)
                 for line in lines[:-1]:
@@ -536,7 +533,7 @@ class WebServiceCaller:
 
         This may mean turning the value into a JSON string.
         """
-        if not isinstance(value, six.string_types):
+        if not isinstance(value, str):
             value = simplejson.dumps(value)
         return quote(value)
 
@@ -560,17 +557,16 @@ class WebServiceAjaxCaller(WebServiceCaller):
     def default_api_version(self):
         """Introduce the Ajax path override to the URI prefix."""
         config = getUtility(IWebServiceConfiguration)
-        default_version = super(WebServiceAjaxCaller, self).default_api_version
+        default_version = super().default_api_version
         return config.path_override + "/" + default_version
 
 
[e-mail]_2_unicode_compatible
 class WebServiceResponseWrapper(ProxyBase):
     """A response from the web service with easy access to the JSON body."""
 
     def __init__(self, response):
         self.body = response.read()
-        super(WebServiceResponseWrapper, self).__init__(response)
+        super().__init__(response)
 
     def getHeader(self, key, default=None):
         return self.getheader(key, default)
@@ -659,7 +655,7 @@ class TestCaseWithWebServiceFixtures(CleanUp, unittest.TestCase):
     """
 
     def setUp(self):
-        super(TestCaseWithWebServiceFixtures, self).setUp()
+        super().setUp()
         # Register a simple configuration object.
         webservice_configuration = WebServiceTestConfiguration()
         sm = getGlobalSiteManager()
@@ -717,7 +713,7 @@ class WebServiceTestCase(TestCaseWithWebServiceFixtures):
 
     def setUp(self):
         """Set the component registry with the given model."""
-        super(WebServiceTestCase, self).setUp()
+        super().setUp()
 
         # Register a service root resource
         sm = getGlobalSiteManager()
@@ -769,12 +765,12 @@ class IGenericEntry(Interface):
     # pylint: disable-msg=E0213
     a_field = exported(
         TextLine(
-            title=u'A "field"',
-            description=u"The only field that can be <> 0 in the entry.",
+            title='A "field"',
+            description="The only field that can be <> 0 in the entry.",
         )
     )
 
-    @operation_parameters(message=TextLine(title=u"Message to say"))
+    @operation_parameters(message=TextLine(title="Message to say"))
     @export_read_operation()
     def greet(message):
         """Print an appropriate greeting based on the message.
@@ -831,4 +827,4 @@ def simple_renderer(value):
     This is a good HTML field renderer to use in tests, because it
     tests Unicode values and embedded HTML.
     """
-    return u"\N{SNOWMAN} <b>%s</b>" % value
+    return "\N{SNOWMAN} <b>%s</b>" % value
diff --git a/src/lazr/restful/tests/test_declarations.py b/src/lazr/restful/tests/test_declarations.py
index f1c688c..305709b 100644
--- a/src/lazr/restful/tests/test_declarations.py
+++ b/src/lazr/restful/tests/test_declarations.py
@@ -2,8 +2,6 @@
 
 """Unit tests for the conversion of interfaces into a web service."""
 
-from __future__ import absolute_import, print_function
-
 import sys
 
 import testtools
@@ -85,7 +83,7 @@ class ContributingInterfacesTestCase(TestCaseWithWebServiceFixtures):
     """Tests for interfaces that contribute fields/operations to others."""
 
     def setUp(self):
-        super(ContributingInterfacesTestCase, self).setUp()
+        super().setUp()
         sm = getSiteManager()
         sm.registerAdapter(ProductToHasBugsAdapter)
         sm.registerAdapter(ProjectToHasBugsAdapter)
@@ -152,7 +150,7 @@ class ContributingInterfacesTestCase(TestCaseWithWebServiceFixtures):
             @exported_as_webservice_entry(contributes_to=[IProduct])
             class IHasTooManyAccessors(Interface):
                 needs_an_accessor = exported(
-                    TextLine(title=u"This needs an accessor", readonly=True)
+                    TextLine(title="This needs an accessor", readonly=True)
                 )
 
                 @accessor_for(needs_an_accessor)
@@ -353,7 +351,7 @@ class ContributingInterfacesTestCase(TestCaseWithWebServiceFixtures):
 
         @exported_as_webservice_entry(contributes_to=[INotExported])
         class IContributor(Interface):
-            title = exported(TextLine(title=u"The project title"))
+            title = exported(TextLine(title="The project title"))
 
         self.assertRaises(
             AttemptToContributeToNonExportedInterface,
@@ -436,7 +434,7 @@ class TestExportAsWebserviceEntry(testtools.TestCase):
     """Tests for export_as_webservice_entry."""
 
     def setUp(self):
-        super(TestExportAsWebserviceEntry, self).setUp()
+        super().setUp()
         if sys.version_info[0] >= 3:
             self.skipTest(
                 "export_as_webservice_entry is only supported on Python 2"
@@ -454,7 +452,7 @@ class TestExportAsWebserviceEntry(testtools.TestCase):
     def test_requires_interface(self):
         # export_as_webservice_entry can only be used on Interface.
         def export_non_interface():
-            class NotAnInterface(object):
+            class NotAnInterface:
                 export_as_webservice_entry()
 
         exception = self.assertRaises(TypeError, export_non_interface)
@@ -478,7 +476,7 @@ class TestExportAsWebserviceCollection(testtools.TestCase):
     """Tests for export_as_webservice_collection."""
 
     def setUp(self):
-        super(TestExportAsWebserviceCollection, self).setUp()
+        super().setUp()
         if sys.version_info[0] >= 3:
             self.skipTest(
                 "export_as_webservice_collection is only supported on "
@@ -568,7 +566,7 @@ class TestExportAsWebserviceCollection(testtools.TestCase):
     def test_requires_interface(self):
         # export_as_webservice_collection can only be used on Interface.
         def export_non_interface():
-            class NotAnInterface(object):
+            class NotAnInterface:
                 export_as_webservice_collection(Interface)
 
         exception = self.assertRaises(TypeError, export_non_interface)
@@ -626,21 +624,21 @@ class TestFindExportedInterfaces(testtools.TestCase):
         )
 
     def test_finds_exported_exceptions(self):
-        class Module(object):
+        class Module:
             NotExportedException_copy = NotExportedException
             ExportedExceptionOne_copy = ExportedExceptionOne
 
         self.assertExportsNames(Module, ["ExportedExceptionOne"])
 
     def test_finds_exported_interfaces(self):
-        class Module(object):
+        class Module:
             INotExported_copy = INotExported
             IExported_copy = IExported
 
         self.assertExportsNames(Module, ["IExported"])
 
     def test_honours_all(self):
-        class Module(object):
+        class Module:
             __all__ = ["ExportedExceptionOne_copy"]
             ExportedExceptionOne_copy = ExportedExceptionOne
             ExportedExceptionTwo_copy = ExportedExceptionTwo
@@ -648,7 +646,7 @@ class TestFindExportedInterfaces(testtools.TestCase):
         self.assertExportsNames(Module, ["ExportedExceptionOne"])
 
     def test_skips_leading_underscore_without_all(self):
-        class Module(object):
+        class Module:
             ExportedExceptionOne_copy = ExportedExceptionOne
             _ExportedExceptionTwo_copy = ExportedExceptionTwo
 
@@ -657,7 +655,7 @@ class TestFindExportedInterfaces(testtools.TestCase):
 
 @exported_as_webservice_entry()
 class IProduct(Interface):
-    title = exported(TextLine(title=u"The product title"))
+    title = exported(TextLine(title="The product title"))
     # Need to define the three attributes below because we have a test which
     # wraps a Product object with a security proxy and later uses adapters
     # that access _dev_branch, _branches and _bug_count.
@@ -668,7 +666,7 @@ class IProduct(Interface):
 
 
 @implementer(IProduct)
-class Product(object):
+class Product:
     title = "A product"
     _bug_count = 0
     _dev_branch = None
@@ -678,21 +676,21 @@ class Product(object):
 
 @exported_as_webservice_entry()
 class IProject(Interface):
-    title = exported(TextLine(title=u"The project title"))
+    title = exported(TextLine(title="The project title"))
 
 
 @implementer(IProject)
-class Project(object):
+class Project:
     title = "A project"
     _bug_count = 0
 
 
 @exported_as_webservice_entry(contributes_to=[IProduct, IProject])
 class IHasBugs(Interface):
-    bug_count = exported(Int(title=u"Number of bugs"))
-    not_exported = TextLine(title=u"Not exported")
+    bug_count = exported(Int(title="Number of bugs"))
+    not_exported = TextLine(title="Not exported")
     bug_target_name = exported(
-        TextLine(title=u"The bug target name of this object.", readonly=True)
+        TextLine(title="The bug target name of this object.", readonly=True)
     )
 
     @export_read_operation()
@@ -726,13 +724,13 @@ class IHasBugs(Interface):
 
 @exported_as_webservice_entry(contributes_to=[IProduct])
 class IHasBugs2(Interface):
-    bug_count = exported(Int(title=u"Number of bugs"))
-    not_exported = TextLine(title=u"Not exported")
+    bug_count = exported(Int(title="Number of bugs"))
+    not_exported = TextLine(title="Not exported")
 
 
 @exported_as_webservice_entry(contributes_to=[IProduct])
 class IHasBugs3(Interface):
-    not_exported = TextLine(title=u"Not exported")
+    not_exported = TextLine(title="Not exported")
 
     @export_read_operation()
     def getBugsCount():
@@ -741,7 +739,7 @@ class IHasBugs3(Interface):
 
 @adapter(IProduct)
 @implementer(IHasBugs)
-class ProductToHasBugsAdapter(object):
+class ProductToHasBugsAdapter:
     def __init__(self, context):
         self.context = context
         self.bug_count = context._bug_count
@@ -766,18 +764,18 @@ class ProjectToHasBugsAdapter(ProductToHasBugsAdapter):
 
 @exported_as_webservice_entry()
 class IBranch(Interface):
-    name = TextLine(title=u"The branch name")
+    name = TextLine(title="The branch name")
 
 
 @implementer(IBranch)
-class Branch(object):
+class Branch:
     def __init__(self, name):
         self.name = name
 
 
 @exported_as_webservice_entry(contributes_to=[IProduct])
 class IHasBranches(Interface):
-    not_exported = TextLine(title=u"Not exported")
+    not_exported = TextLine(title="Not exported")
     development_branch = exported(
         Reference(schema=IBranch, readonly=True),
         ("2.0", dict(exported_as="development_branch_20")),
@@ -804,7 +802,7 @@ class IHasBranches(Interface):
 
 @adapter(IProduct)
 @implementer(IHasBranches)
-class ProductToHasBranchesAdapter(object):
+class ProductToHasBranchesAdapter:
     def __init__(self, context):
         self.context = context
 
@@ -876,7 +874,7 @@ class TestEntryMultiversion(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             INotInitiallyExported,
             [],
-            *getUtility(IWebServiceConfiguration).active_versions
+            *getUtility(IWebServiceConfiguration).active_versions,
         )
         self.assertEqual(len(interfaces), 1)
         self.assertEqual(interfaces[0].version, "2.0")
@@ -887,7 +885,7 @@ class TestEntryMultiversion(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             INotPresentInLaterVersion,
             [],
-            *getUtility(IWebServiceConfiguration).active_versions
+            *getUtility(IWebServiceConfiguration).active_versions,
         )
         self.assertEqual(len(interfaces), 1)
         self.assertEqual(interfaces[0].version, "1.0")
@@ -898,7 +896,7 @@ class TestEntryMultiversion(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             IHasDifferentNamesInDifferentVersions,
             [],
-            *getUtility(IWebServiceConfiguration).active_versions
+            *getUtility(IWebServiceConfiguration).active_versions,
         )
         interface_10 = interfaces[0].object
         tags_10 = interface_10.getTaggedValue(LAZR_WEBSERVICE_NAME)
@@ -936,7 +934,7 @@ class TestEntryMultiversion(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             IHasDifferentSingularNamesInDifferentVersions,
             [],
-            *getUtility(IWebServiceConfiguration).active_versions
+            *getUtility(IWebServiceConfiguration).active_versions,
         )
         interface_10 = interfaces[0].object
         tags_10 = interface_10.getTaggedValue(LAZR_WEBSERVICE_NAME)
@@ -1024,7 +1022,7 @@ class IFieldExplicitOperationDefinition(Interface):
 
 
 @implementer(IFieldExplicitOperationDefinition)
-class FieldExplicitOperationDefinition(object):
+class FieldExplicitOperationDefinition:
     pass
 
 
@@ -1032,7 +1030,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
     """Test behavior when require_explicit_versions is True."""
 
     def setUp(self):
-        super(TestRequireExplicitVersions, self).setUp()
+        super().setUp()
         self.utility = getUtility(IWebServiceConfiguration)
         self.utility.require_explicit_versions = True
 
@@ -1061,7 +1059,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
             generate_entry_interfaces,
             IEntryExportedWithoutAsOf,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         self.assertEqual(
             str(exception),
@@ -1078,7 +1076,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             IFieldExportedToEarliestVersionUsingAsOf,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         interface_10 = interfaces[0].object
         interface_20 = interfaces[1].object
@@ -1093,7 +1091,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
         interfaces = generate_entry_interfaces(
             IFieldExportedToLatestVersionUsingAsOf,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         interface_10 = interfaces[0].object
         interface_20 = interfaces[1].object
@@ -1108,7 +1106,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
             generate_entry_interfaces,
             IFieldExportedWithoutAsOf,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         self.assertEqual(
             str(exception),
@@ -1140,7 +1138,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
             generate_entry_interfaces,
             IFieldAsOfNonexistentVersion,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         self.assertEqual(
             str(exception),
@@ -1158,7 +1156,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
             generate_entry_interfaces,
             IFieldDoubleDefinition,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         self.assertEqual(
             str(exception),
@@ -1176,7 +1174,7 @@ class TestRequireExplicitVersions(TestCaseWithWebServiceFixtures):
             generate_entry_interfaces,
             IFieldDefiningAttributesBeforeAsOf,
             [],
-            *self.utility.active_versions
+            *self.utility.active_versions,
         )
         self.assertEqual(
             str(exception),
@@ -1370,7 +1368,7 @@ class TestCoherenceChecking(TestCaseWithWebServiceFixtures):
             ValueError,
             register_test_module,
             "testmod",
-            *(list(classes) + [expect_failure_due_to_interface])
+            *(list(classes) + [expect_failure_due_to_interface]),
         )
         expected_message = (
             "In version %(version)s, %(reason)s, but version %(version)s "
diff --git a/src/lazr/restful/tests/test_docs.py b/src/lazr/restful/tests/test_docs.py
index a503ae6..26f9645 100644
--- a/src/lazr/restful/tests/test_docs.py
+++ b/src/lazr/restful/tests/test_docs.py
@@ -17,9 +17,6 @@
 
 # pylint: disable=E0611,W0142
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = []
 
 import atexit
@@ -66,19 +63,14 @@ def load_tests(loader, tests, pattern):
                     )
                 )
     atexit.register(cleanup_resources)
-    globs = {
-        "absolute_import": absolute_import,
-        "print_function": print_function,
-    }
     tests.addTest(
         doctest.DocFileSuite(
             *doctest_files,
             module_relative=False,
             optionflags=DOCTEST_FLAGS,
             tearDown=tearDown,
-            globs=globs,
             encoding="UTF-8",
-            checker=checker
+            checker=checker,
         )
     )
     return tests
diff --git a/src/lazr/restful/tests/test_error.py b/src/lazr/restful/tests/test_error.py
index d407ccb..69adf07 100644
--- a/src/lazr/restful/tests/test_error.py
+++ b/src/lazr/restful/tests/test_error.py
@@ -2,10 +2,6 @@
 
 """Tests of lazr.restful navigation."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 from pkg_resources import resource_filename
 import os
 import traceback
@@ -30,7 +26,7 @@ from lazr.restful.testing.webservice import FakeRequest
 class TestResource(ReadWriteResource):
     def __init__(self, callable, request):
         self.callable = callable
-        super(TestResource, self).__init__(context=None, request=request)
+        super().__init__(context=None, request=request)
 
     def do_GET(self):
         return self.callable()
@@ -57,7 +53,7 @@ class ErrorsTestCase(unittest.TestCase):
             pass
 
         self.exception_class = MyException
-        super(ErrorsTestCase, self).setUp()
+        super().setUp()
 
     def test_decorated_exception_class_becomes_error_view(self):
         # An exposed exception, when raised, will set the response
@@ -140,7 +136,7 @@ class ErrorsTestCase(unittest.TestCase):
         # Register a view for the exception that does not subclass
         # WebServiceExceptionView and provides no information about
         # which HTTP status code should be used.
-        class ViewHasNoStatus(object):
+        class ViewHasNoStatus:
             def __init__(*args):
                 pass
 
diff --git a/src/lazr/restful/tests/test_etag.py b/src/lazr/restful/tests/test_etag.py
index ed9a950..e9421a0 100644
--- a/src/lazr/restful/tests/test_etag.py
+++ b/src/lazr/restful/tests/test_etag.py
@@ -1,10 +1,6 @@
 # Copyright 2008 Canonical Ltd.  All rights reserved.
 """Tests for ETag generation."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 from collections import OrderedDict
 from datetime import (
     date,
@@ -178,11 +174,11 @@ class EntryFieldResourceTests(unittest.TestCase):
         self.set_field_value("this is the field value")
 
         # Find the cores generated with a given revision...
-        self.config.code_revision = u"42"
+        self.config.code_revision = "42"
         first_cores = self.resource._getETagCores(self.resource.JSON_TYPE)
 
         # ...find the cores generated with a different revision.
-        self.config.code_revision = u"99"
+        self.config.code_revision = "99"
         second_cores = self.resource._getETagCores(self.resource.JSON_TYPE)
 
         # The cores should be different.
@@ -223,11 +219,11 @@ class ServiceRootResourceTests(unittest.TestCase):
         # web service change.
 
         # Find the cores generated with a given revision...
-        self.config.code_revision = u"42"
+        self.config.code_revision = "42"
         first_cores = self.resource._getETagCores(self.resource.JSON_TYPE)
 
         # ...find the cores generated with a different revision.
-        self.config.code_revision = u"99"
+        self.config.code_revision = "99"
         second_cores = self.resource._getETagCores(self.resource.JSON_TYPE)
 
         # The cores should be different.
@@ -240,12 +236,12 @@ class ServiceRootResourceTests(unittest.TestCase):
         # information.)
 
         # Find the ETag generated with a given revision...
-        self.config.code_revision = u"42"
+        self.config.code_revision = "42"
         first_etag = self.resource.getETag(self.resource.WADL_TYPE)
 
         # ...and find the ETag generated with a different revision.
         self.resource.etags_by_media_type = {}
-        self.config.code_revision = u"99"
+        self.config.code_revision = "99"
         second_etag = self.resource.getETag(self.resource.WADL_TYPE)
 
         # The ETags should be different.
diff --git a/src/lazr/restful/tests/test_navigation.py b/src/lazr/restful/tests/test_navigation.py
index 568205e..ec5cc6d 100644
--- a/src/lazr/restful/tests/test_navigation.py
+++ b/src/lazr/restful/tests/test_navigation.py
@@ -2,10 +2,6 @@
 
 """Tests of lazr.restful navigation."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 import unittest
 
 from zope.component import (
@@ -34,14 +30,14 @@ from lazr.restful.testing.webservice import FakeRequest
 class IChild(Interface):
     """Interface for a simple entry."""
 
-    one = Text(title=u"One")
-    two = Text(title=u"Two")
+    one = Text(title="One")
+    two = Text(title="Two")
 
 
 class IParent(Interface):
     """Interface for a simple entry that contains another entry."""
 
-    three = Text(title=u"Three")
+    three = Text(title="Three")
     child = Reference(schema=IChild)
 
 
@@ -49,8 +45,8 @@ class IParent(Interface):
 class Child:
     """A simple implementation of IChild."""
 
-    one = u"one"
-    two = u"two"
+    one = "one"
+    two = "two"
 
 
 class ChildEntry:
@@ -66,7 +62,7 @@ class ChildEntry:
 class Parent:
     """A simple implementation of IParent."""
 
-    three = u"three"
+    three = "three"
     child = Child()
 
 
diff --git a/src/lazr/restful/tests/test_utils.py b/src/lazr/restful/tests/test_utils.py
index d095e02..db180d0 100644
--- a/src/lazr/restful/tests/test_utils.py
+++ b/src/lazr/restful/tests/test_utils.py
@@ -2,10 +2,6 @@
 
 """Test for lazr.restful.utils."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 import random
 import testtools
 import unittest
@@ -101,7 +97,7 @@ class TestUtils(unittest.TestCase):
 
 class TestVersionedDict(testtools.TestCase):
     def setUp(self):
-        super(TestVersionedDict, self).setUp()
+        super().setUp()
         self.dict = VersionedDict()
 
     def test_rename_version_works(self):
diff --git a/src/lazr/restful/tests/test_webservice.py b/src/lazr/restful/tests/test_webservice.py
index 4864150..e8c8010 100644
--- a/src/lazr/restful/tests/test_webservice.py
+++ b/src/lazr/restful/tests/test_webservice.py
@@ -2,10 +2,6 @@
 
 """Test for the WADL generation."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
-
 from contextlib import contextmanager
 from io import (
     BytesIO,
@@ -19,7 +15,6 @@ import re
 import simplejson
 import unittest
 
-import six
 from zope.component import (
     eventtesting,
     getGlobalSiteManager,
@@ -256,7 +251,7 @@ class EntryTestCase(WebServiceTestCase):
 class IHasOneField(Interface):
     """An entry with a single field."""
 
-    a_field = exported(TextLine(title=u"A field."))
+    a_field = exported(TextLine(title="A field."))
 
 
 @implementer(IHasOneField)
@@ -271,8 +266,8 @@ class HasOneField:
 class IHasTwoFields(Interface):
     """An entry with two fields."""
 
-    a_field = exported(TextLine(title=u"A field."))
-    another_field = exported(TextLine(title=u"Another field."))
+    a_field = exported(TextLine(title="A field."))
+    another_field = exported(TextLine(title="Another field."))
 
 
 @implementer(IHasTwoFields)
@@ -353,7 +348,7 @@ class TestEntryWebLink(EntryTestCase):
 class IHasNoWebLink(Interface):
     """An entry that does not publish a web_link."""
 
-    a_field = exported(TextLine(title=u"A field."))
+    a_field = exported(TextLine(title="A field."))
 
 
 @implementer(IHasNoWebLink)
@@ -383,7 +378,7 @@ class InterfaceRestrictedField(TextLine):
 
     def __init__(self, restrict_to_interface, *args, **kwargs):
         self.restrict_to_interface = restrict_to_interface
-        super(InterfaceRestrictedField, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def bind(self, context):
         if not self.restrict_to_interface.providedBy(context):
@@ -391,7 +386,7 @@ class InterfaceRestrictedField(TextLine):
                 "InterfaceRestrictedField can only be used with %s"
                 % self.restrict_to_interface.__name__
             )
-        return super(InterfaceRestrictedField, self).bind(context)
+        return super().bind(context)
 
 
 @exported_as_webservice_entry()
@@ -413,7 +408,7 @@ class HasRestrictedField:
 class IHasFieldExportedAsDifferentName(Interface):
     """An entry with a field exported as a different name."""
 
-    a_field = exported(TextLine(title=u"A field."), exported_as="field")
+    a_field = exported(TextLine(title="A field."), exported_as="field")
 
 
 @implementer(IHasFieldExportedAsDifferentName)
@@ -437,7 +432,7 @@ class TestEntryWrite(EntryTestCase):
         # If web_link is not published, applyChanges rejects a request
         # that references it.
         with self.entry_resource(HasOneField, "") as resource:
-            errors = resource.applyChanges({"web_link": u"some_value"})
+            errors = resource.applyChanges({"web_link": "some_value"})
             self.assertEqual(
                 errors,
                 "web_link: You tried to modify a nonexistent attribute.",
@@ -448,7 +443,7 @@ class TestEntryWrite(EntryTestCase):
         self._register_website_url_space(IHasOneField)
 
         with self.entry_resource(HasOneField, "") as resource:
-            errors = resource.applyChanges({"web_link": u"some_value"})
+            errors = resource.applyChanges({"web_link": "some_value"})
             self.assertEqual(
                 errors, "web_link: You tried to modify a read-only attribute."
             )
@@ -484,7 +479,7 @@ class TestEntryWrite(EntryTestCase):
 
         with self.entry_resource(
             HasFieldExportedAsDifferentName,
-            u"initial value",
+            "initial value",
         ) as resource:
             # We have an entry that has a different name on the
             # entry than on its context.
@@ -492,13 +487,13 @@ class TestEntryWrite(EntryTestCase):
             self.assertEqual(entry.field, entry.context.a_field)
             # This populates the cache.
             self.assertEqual(
-                u"initial value", resource.toDataForJSON()["field"]
+                "initial value", resource.toDataForJSON()["field"]
             )
             # This returns the changed value.
             representation = simplejson.loads(
-                resource.applyChanges(dict(field=u"new value"))
+                resource.applyChanges(dict(field="new value"))
             )
-            self.assertEqual(u"new value", representation["field"])
+            self.assertEqual("new value", representation["field"])
 
 
 class TestEntryWriteForRestrictedField(EntryTestCase):
@@ -518,7 +513,7 @@ class TestEntryWriteForRestrictedField(EntryTestCase):
             entry = resource.entry
             entry.schema["a_field"].restrict_to_interface = IHasRestrictedField
             self.assertEqual(entry.a_field, "")
-            resource.applyChanges({"a_field": u"a_value"})
+            resource.applyChanges({"a_field": "a_value"})
             self.assertEqual(entry.a_field, "a_value")
 
             # Make sure that IHasRestrictedField itself works correctly.
@@ -531,7 +526,7 @@ class TestEntryWriteForRestrictedField(EntryTestCase):
             self.assertRaises(
                 AssertionError,
                 resource.applyChanges,
-                {"a_field": u"a_new_value"},
+                {"a_field": "a_new_value"},
             )
             self.assertEqual(resource.entry.a_field, "a_value")
 
@@ -542,9 +537,9 @@ class HTMLRepresentationTest(EntryTestCase):
     default_media_type = "application/xhtml+xml"
 
     def setUp(self):
-        super(HTMLRepresentationTest, self).setUp()
+        super().setUp()
         self._register_url_adapter(IHasOneField)
-        self.unicode_message = u"Hello from a \N{SNOWMAN}"
+        self.unicode_message = "Hello from a \N{SNOWMAN}"
         self.utf8_message = self.unicode_message.encode("utf-8")
 
     def test_entry_html_representation_is_utf8(self):
@@ -567,15 +562,13 @@ class JSONPlusHTMLRepresentationTest(EntryTestCase):
     testmodule_objects = [HasTwoFields, IHasTwoFields]
 
     def setUp(self):
-        super(JSONPlusHTMLRepresentationTest, self).setUp()
+        super().setUp()
         self.default_media_type = "application/json;include=lp_html"
         self._register_url_adapter(IHasTwoFields)
 
     def register_html_field_renderer(self, name=""):
         """Simplify the register_html_field_renderer call."""
-        super(
-            JSONPlusHTMLRepresentationTest, self
-        ).register_html_field_renderer(
+        super().register_html_field_renderer(
             IHasTwoFields, ITextLine, simple_renderer, name
         )
 
@@ -584,8 +577,8 @@ class JSONPlusHTMLRepresentationTest(EntryTestCase):
         """Simplify the entry_resource call."""
         with self.entry_resource(
             HasTwoFields,
-            six.text_type(value_1),
-            six.text_type(value_2),
+            str(value_1),
+            str(value_2),
         ) as resource:
             yield resource
 
@@ -654,7 +647,7 @@ class JSONPlusHTMLRepresentationTest(EntryTestCase):
         with self.resource() as resource:
             json_plus_xhtml = resource.JSON_PLUS_XHTML_TYPE
             json = simplejson.loads(
-                six.text_type(resource._representation(json_plus_xhtml))
+                str(resource._representation(json_plus_xhtml))
             )
             resource.applyChanges(json, json_plus_xhtml)
             self.assertEqual(resource.request.response.getStatus(), 209)
@@ -664,9 +657,7 @@ class JSONPlusHTMLRepresentationTest(EntryTestCase):
         json = None
         with self.resource() as resource:
             json = simplejson.loads(
-                six.text_type(
-                    resource._representation(resource.JSON_PLUS_XHTML_TYPE)
-                )
+                str(resource._representation(resource.JSON_PLUS_XHTML_TYPE))
             )
             resource.applyChanges(json, resource.JSON_TYPE)
             self.assertEqual(resource.request.response.getStatus(), 400)
@@ -676,7 +667,7 @@ class UnicodeChoice(EnumeratedType):
     """A choice between an ASCII value and a Unicode value."""
 
     ASCII = Item("Ascii", "Ascii choice")
-    UNICODE = Item(u"Uni\u00e7ode", "Uni\u00e7ode choice")
+    UNICODE = Item("Uni\u00e7ode", "Uni\u00e7ode choice")
 
 
 @exported_as_webservice_entry()
@@ -686,7 +677,7 @@ class ICanBeSetToUnicodeValue(Interface):
     a_field = exported(
         Choice(
             vocabulary=UnicodeChoice,
-            title=u"A value that might be ASCII or Unicode.",
+            title="A value that might be ASCII or Unicode.",
             required=False,
             default=None,
         )
@@ -707,7 +698,7 @@ class UnicodeErrorTestCase(EntryTestCase):
     testmodule_objects = [CanBeSetToUnicodeValue, ICanBeSetToUnicodeValue]
 
     def setUp(self):
-        super(UnicodeErrorTestCase, self).setUp()
+        super().setUp()
         self._register_url_adapter(ICanBeSetToUnicodeValue)
 
     def test_unicode_error(self):
@@ -715,14 +706,14 @@ class UnicodeErrorTestCase(EntryTestCase):
 
             # This will raise an exception, which will cause the request
             # to fail with a 400 error code.
-            error = resource.applyChanges({"a_field": u"No such value"})
+            error = resource.applyChanges({"a_field": "No such value"})
             self.assertEqual(resource.request.response.getStatus(), 400)
 
             # The error message is a Unicode string which mentions both
             # the ASCII value and the Unicode value,
             expected_error = (
-                u'a_field: Invalid value "No such value". Acceptable values '
-                u"are: Ascii, Uni\u00e7ode"
+                'a_field: Invalid value "No such value". Acceptable values '
+                "are: Ascii, Uni\u00e7ode"
             )
             self.assertEqual(error, expected_error)
 
@@ -887,7 +878,7 @@ class DuplicateNameTestCase(WebServiceTestCase):
 def make_entry(name):
     """Make an entity with some attibutes to expose as a web service."""
     fields = {
-        "%s_field" % letter: exported(TextLine(title=u"Field %s" % letter))
+        "%s_field" % letter: exported(TextLine(title="Field %s" % letter))
         for letter in "rstuvwxyz"
     }
     cls = InterfaceClass(name, bases=(Interface,), attrs=fields)
@@ -901,7 +892,7 @@ class TestWadlDeterminism(WebServiceTestCase):
         # make some -- randomly ordered -- objects to use to build the WADL
         self.testmodule_objects = [make_entry(name) for name in "abcdefghijk"]
         random.shuffle(self.testmodule_objects)
-        super(TestWadlDeterminism, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     @property
     def wadl(self):
@@ -1026,7 +1017,7 @@ class BaseBatchingTest:
     testmodule_objects = [HasRestrictedField, IHasRestrictedField]
 
     def setUp(self):
-        super(BaseBatchingTest, self).setUp()
+        super().setUp()
         # Register TestEntry as the IEntry implementation for ITestEntry.
         getGlobalSiteManager().registerAdapter(
             TestEntry, [ITestEntry, IWebServiceClientRequest], provided=IEntry
@@ -1100,7 +1091,7 @@ class NotificationsProviderTest(EntryTestCase):
             ]
 
     def setUp(self):
-        super(NotificationsProviderTest, self).setUp()
+        super().setUp()
         self.default_media_type = "application/json;include=lp_html"
         self._register_website_url_space(IHasOneField)
         self._register_notification_adapter()
@@ -1146,7 +1137,7 @@ class EventTestCase(EntryTestCase):
     testmodule_objects = [IHasOneField]
 
     def setUp(self):
-        super(EventTestCase, self).setUp()
+        super().setUp()
         self._register_url_adapter(IHasOneField)
         eventtesting.setUp()
 
@@ -1154,7 +1145,7 @@ class EventTestCase(EntryTestCase):
         # Passing in a non-empty changeset spawns an
         # IObjectModifiedEvent.
         with self.entry_resource(HasOneField, "") as resource:
-            resource.applyChanges({"a_field": u"Some value"})
+            resource.applyChanges({"a_field": "Some value"})
         events = eventtesting.getEvents()
         self.assertEqual(len(events), 1)
         event = events[0]
@@ -1175,9 +1166,9 @@ class MalformedRequest(EntryTestCase):
     default_media_type = "application/xhtml+xml"
 
     def setUp(self):
-        super(MalformedRequest, self).setUp()
+        super().setUp()
         self._register_url_adapter(IHasOneField)
-        self.unicode_message = u"Hello from a \N{SNOWMAN}"
+        self.unicode_message = "Hello from a \N{SNOWMAN}"
 
     def test_multiple_named_operations_generate_error_on_GET(self):
         with self.entry_resource(
diff --git a/src/lazr/restful/utils.py b/src/lazr/restful/utils.py
index 043ed87..2175977 100644
--- a/src/lazr/restful/utils.py
+++ b/src/lazr/restful/utils.py
@@ -2,9 +2,6 @@
 
 """Various utility functions."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "camelcase_to_underscore_separated",
     "get_current_browser_request",
@@ -20,7 +17,7 @@ __all__ = [
     "VersionedObject",
 ]
 
-
+import builtins
 import collections
 import copy
 import operator
@@ -28,8 +25,6 @@ import re
 import string
 import subprocess
 
-import six
-
 from zope.component import getUtility
 from zope.schema import getFieldsInOrder
 from zope.interface import alsoProvides, classImplements
@@ -134,7 +129,7 @@ VersionedObject = collections.namedtuple(
 )
 
 
-class VersionedDict(object):
+class VersionedDict:
     """A stack of named dictionaries.
 
     Most access to the stack actually operates on the dictionary on
@@ -368,9 +363,11 @@ def safe_hasattr(ob, name):
 
 def smartquote(str):
     """Return a copy of the string, with typographical quote marks applied."""
-    str = six.text_type(str)
-    str = re.compile(u'(^| )(")([^" ])').sub(u"\\1\u201c\\3", str)
-    str = re.compile(u'([^ "])(")($|[\\s.,;:!?])').sub(u"\\1\u201d\\3", str)
+    # Using builtins.str here is weird, but it lets us cope with the
+    # unfortunate naming of our positional argument without breaking API.
+    str = builtins.str(str)
+    str = re.compile('(^| )(")([^" ])').sub("\\1\u201c\\3", str)
+    str = re.compile('([^ "])(")($|[\\s.,;:!?])').sub("\\1\u201d\\3", str)
     return str
 
 
diff --git a/src/lazr/restful/wsgi.py b/src/lazr/restful/wsgi.py
index 2b03ab3..fc298e0 100644
--- a/src/lazr/restful/wsgi.py
+++ b/src/lazr/restful/wsgi.py
@@ -1,8 +1,5 @@
 """A WSGI application for a lazr.restful web service."""
 
-from __future__ import absolute_import, print_function
-
-__metaclass__ = type
 __all__ = [
     "BaseWSGIWebServiceConfiguration",
     "WSGIApplication",