Drop support for Python 2.7 up to 3.6.

setup.py

@@ -29,7 +29,7 @@ def read(path):
     name='z3c.preference',
     version='2.0.dev0',
     author="Michael Howitz",
-    author_email="zope-dev@zope.org",
+    author_email="zope-dev@zope.dev",
     description="UI for zope.preference using z3c.pagelet and z3c.form.",
     long_description='\n\n'.join([
             read('README.rst'),
@@ -66,6 +66,7 @@ def read(path):
     include_package_data=True,
     package_dir={'': 'src'},
     namespace_packages=['z3c'],
+    python_requires='>=3.7',
     extras_require=dict(
         test=[
             'zope.app.wsgi >= 3.7',

src/z3c/preference/browser.py

@@ -31,7 +31,7 @@ class EditForm(z3c.formui.form.EditForm):
     """Edit form for preference groups."""
 
     def __init__(self, *args, **kw):
-        super(EditForm, self).__init__(*args, **kw)
+        super().__init__(*args, **kw)
         self.label = self.context.__title__
         self.description = self.context.__description__
         self.fields = to_fields(self.context)
@@ -41,7 +41,7 @@ class PreferenceGroup(z3c.form.group.Group):
     """z3c.form group of a preference group."""
 
     def __init__(self, *args, **kw):
-        super(PreferenceGroup, self).__init__(*args, **kw)
+        super().__init__(*args, **kw)
         self.fields = to_fields(self.context)
         self.description = self.context.__description__
         self.label = self.context.__title__
@@ -52,7 +52,7 @@ class CategoryEditForm(z3c.form.group.GroupForm,
     """Edit form for preference categories."""
 
     def __init__(self, *args, **kw):
-        super(CategoryEditForm, self).__init__(*args, **kw)
+        super().__init__(*args, **kw)
         sorted_prefs = sorted(self.context.items(), key=lambda x: x[0])
         groups = [PreferenceGroup(pref, self.request, self)
                   for key, pref in sorted_prefs]

src/z3c/preference/testing.py

@@ -23,12 +23,12 @@ class BrowserLayer(zope.testbrowser.wsgi.Layer,
     """BrowserLayer which is compatible with zope.testbrowser."""
 
     def testSetUp(self):
-        super(BrowserLayer, self).testSetUp()
+        super().testSetUp()
         self._application.requestFactory._db = self.db
 
     def testTearDown(self):
         self._application.requestFactory._publication_cache.clear()
-        super(BrowserLayer, self).testTearDown()
+        super().testTearDown()
 
     make_wsgi_app = zope.app.wsgi.testlayer.BrowserLayer.make_wsgi_app