remove py35 compatibility code

as f-strings are heavily used now, compatibility to py35
can be removed

Change-Id: I1ae4912ad4cbde8419b74845217943bd061053f3
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/32754
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

frappy/modulebase.py

@@ -109,8 +109,6 @@ class HasAccessibles(HasProperties):
         for aname in new_names:
             if aname not in paramOrder:
                 accessibles.move_to_end(aname)
-        # note: for python < 3.6 the order of inherited items is not ensured between
-        # declarations within the same class
         cls.accessibles = accessibles
 
         cls.wrappedAttributes = {'isWrapped': True}

frappy/properties.py

@@ -27,12 +27,11 @@ import inspect
 
 from frappy.errors import BadValueError, ConfigError, ProgrammingError
 from frappy.lib import UniqueObject
-from frappy.lib.py35compat import Object
 
 UNSET = UniqueObject('undefined value')  #: an unset value, not even None
 
 
-class HasDescriptors(Object):
+class HasDescriptors:
     @classmethod
     def __init_subclass__(cls):
         # when migrating old style declarations, sometimes the trailing comma is not removed

frappy/protocol/interface/tcp.py

@@ -232,13 +232,6 @@ class TCPServer(DualStackTCPServer):
             self.log.warning('tried again %d times after "Address already in use"', ntry)
         self.log.info("TCPServer initiated")
 
-    # py35 compatibility
-    if not hasattr(socketserver.ThreadingTCPServer, '__exit__'):
-        def __enter__(self):
-            return self
-
-        def __exit__(self, *args):
-            self.server_close()
 
 def format_address(addr):
     if len(addr) == 2: