diff --git a/ldapcherry/__init__.py b/ldapcherry/__init__.py
index a7d5c18..33b2063 100644
--- a/ldapcherry/__init__.py
+++ b/ldapcherry/__init__.py
@@ -15,10 +15,9 @@ import logging
 import logging.handlers
 from operator import itemgetter
 from socket import error as socket_error
-import urllib
 import cgi
 
-from exceptions import *
+from ldapcherry.exceptions import *
 from ldapcherry.lclogging import *
 from ldapcherry.roles import Roles
 from ldapcherry.attributes import Attributes
@@ -31,7 +30,13 @@ from cherrypy.lib.httputil import parse_query_string
 from mako.template import Template
 from mako import lookup
 from mako import exceptions
-from sets import Set
+
+
+if sys.version < '3':
+    from sets import Set as set
+    from urllib import quote_plus
+else:
+    from urllib.parse import quote_plus
 
 SESSION_KEY = '_cp_username'
 
@@ -68,8 +73,8 @@ class LdapCherry(object):
                 data[d] = self._escape_list(data[d])
             elif isinstance(data[d], dict):
                 data[d] = self._escape_dict(data[d])
-            elif isinstance(data[d], Set):
-                data[d] = Set(self._escape_list(data[d]))
+            elif isinstance(data[d], set):
+                data[d] = set(self._escape_list(data[d]))
             else:
                 data[d] = cgi.escape(data[d], True)
         return data
@@ -178,7 +183,7 @@ class LdapCherry(object):
             except Exception as e:
                 raise MissingParameter('backends', backend + '.module')
             try:
-                bc = __import__(module, globals(), locals(), ['Backend'], -1)
+                bc = __import__(module, globals(), locals(), ['Backend'], 0)
             except Exception as e:
                 self._handle_exception(e)
                 raise BackendModuleLoadingFail(module)
@@ -219,7 +224,7 @@ class LdapCherry(object):
             'ldapcherry.ppolicy'
         )
         try:
-            pp = __import__(module, globals(), locals(), ['PPolicy'], -1)
+            pp = __import__(module, globals(), locals(), ['PPolicy'], 0)
         except:
             raise BackendModuleLoadingFail(module)
         if 'ppolicy' in config:
@@ -590,7 +595,7 @@ class LdapCherry(object):
         else:
             qs = '?' + cherrypy.request.query_string
         # Escaped version of the requested URL
-        quoted_requrl = urllib.quote_plus(cherrypy.url() + qs)
+        quoted_requrl = quote_plus(cherrypy.url() + qs)
         if not username:
             # return to login page (with quoted url in query string)
             if redir_login:
@@ -695,7 +700,7 @@ class LdapCherry(object):
                 roles.append(r)
         groups = self.roles.get_groups(roles)
         for b in groups:
-            self.backends[b].add_to_groups(username, Set(groups[b]))
+            self.backends[b].add_to_groups(username, set(groups[b]))
 
         cherrypy.log.error(
             msg="user '" + username + "' made member of " +
@@ -823,10 +828,10 @@ class LdapCherry(object):
                 if b not in g:
                     g[b] = []
             tmp = \
-                Set(groups_add[b]) - \
-                Set(groups_keep[b]) - \
-                Set(groups_current[b]) - \
-                Set(lonely_groups[b])
+                set(groups_add[b]) - \
+                set(groups_keep[b]) - \
+                set(groups_current[b]) - \
+                set(lonely_groups[b])
             cherrypy.log.error(
                 msg="user '" + username + "' added to groups: " +
                     str(list(tmp)) + " in backend '" + b + "'",
@@ -840,11 +845,11 @@ class LdapCherry(object):
                     g[b] = []
             tmp = \
                 (
-                    (Set(groups_rm[b]) | Set(groups_remove[b])) -
-                    (Set(groups_keep[b]) | Set(groups_add[b]))
+                    (set(groups_rm[b]) | set(groups_remove[b])) -
+                    (set(groups_keep[b]) | set(groups_add[b]))
                 ) & \
                 (
-                    Set(groups_current[b]) | Set(lonely_groups[b])
+                    set(groups_current[b]) | set(lonely_groups[b])
                 )
             cherrypy.log.error(
                 msg="user '" + username + "' removed from groups: " +
@@ -933,7 +938,7 @@ class LdapCherry(object):
             if url is None:
                 qs = ''
             else:
-                qs = '?url=' + urllib.quote_plus(url)
+                qs = '?url=' + quote_plus(url)
             raise cherrypy.HTTPRedirect("/signin" + qs)
 
     @cherrypy.expose
diff --git a/ldapcherry/attributes.py b/ldapcherry/attributes.py
index 01fa396..75c863e 100644
--- a/ldapcherry/attributes.py
+++ b/ldapcherry/attributes.py
@@ -12,9 +12,11 @@ import re
 from ldapcherry.pyyamlwrapper import loadNoDump
 from ldapcherry.pyyamlwrapper import DumplicatedKey
 from ldapcherry.exceptions import *
-from sets import Set
 import yaml
 
+if sys.version < '3':
+    from sets import Set as set
+
 # List of available types for form
 types = ['string', 'textfield', 'email', 'int', 'stringlist',
          'fix', 'password']
@@ -24,7 +26,7 @@ class Attributes:
 
     def __init__(self, attributes_file):
         self.attributes_file = attributes_file
-        self.backends = Set([])
+        self.backends = set([])
         self.self_attributes = {}
         self.backend_attributes = {}
         self.displayed_attributes = {}
diff --git a/ldapcherry/backend/backendDemo.py b/ldapcherry/backend/backendDemo.py
index db3559b..0377bad 100644
--- a/ldapcherry/backend/backendDemo.py
+++ b/ldapcherry/backend/backendDemo.py
@@ -7,7 +7,11 @@
 
 # This is a demo backend
 
-from sets import Set
+
+import sys
+if sys.version < '3':
+    from sets import Set as set
+
 import ldapcherry.backend
 from ldapcherry.exceptions import UserDoesntExist, \
     GroupDoesntExist, MissingParameter, \
@@ -37,12 +41,12 @@ class Backend(ldapcherry.backend.Backend):
         self.backend_name = name
         admin_user = self.get_param('admin.user', 'admin')
         admin_password = self.get_param('admin.password', 'admin')
-        admin_groups = Set(re.split('\W+', self.get_param('admin.groups')))
+        admin_groups = set(self._basic_splitter(self.get_param('admin.groups')))
         basic_user = self.get_param('basic.user', 'user')
         basic_password = self.get_param('basic.password', 'user')
-        basic_groups = Set(re.split('\W+', self.get_param('basic.groups')))
+        basic_groups = set(self._basic_splitter(self.get_param('basic.groups')))
         pwd_attr = self.get_param('pwd_attr')
-        self.search_attrs = Set(
+        self.search_attrs = set(
             re.split('\W+', self.get_param('search_attributes')),
             )
         self.pwd_attr = pwd_attr
@@ -60,6 +64,10 @@ class Backend(ldapcherry.backend.Backend):
                 'groups': basic_groups,
                 }
 
+    @staticmethod
+    def _basic_splitter(in_str):
+        return [re.sub(r'(?<!\\)\\', '', x) for x in re.split(r'(?<!\\),\W*', in_str)]
+
     def _check_fix_users(self, username):
         if self.admin_user == username or self.basic_user == username:
             raise Exception('User cannot be modified')
@@ -91,7 +99,7 @@ class Backend(ldapcherry.backend.Backend):
         if username in self.users:
             raise UserAlreadyExists(username, self.backend_name)
         self.users[username] = attrs
-        self.users[username]['groups'] = Set([])
+        self.users[username]['groups'] = set([])
 
     def del_user(self, username):
         """ Delete a user from the backend
@@ -107,7 +115,7 @@ class Backend(ldapcherry.backend.Backend):
             raise UserDoesntExist(username, self.backend_name)
 
     def set_attrs(self, username, attrs):
-        """ Set a list of attributes for a given user
+        """ set a list of attributes for a given user
 
         :param username: 'key' attribute of the user
         :type username: string
@@ -128,7 +136,7 @@ class Backend(ldapcherry.backend.Backend):
         """
         self._check_fix_users(username)
         current_groups = self.users[username]['groups']
-        new_groups = current_groups | Set(groups)
+        new_groups = current_groups | set(groups)
         self.users[username]['groups'] = new_groups
 
     def del_from_groups(self, username, groups):
@@ -143,7 +151,7 @@ class Backend(ldapcherry.backend.Backend):
         """
         self._check_fix_users(username)
         current_groups = self.users[username]['groups']
-        new_groups = current_groups - Set(groups)
+        new_groups = current_groups - set(groups)
         self.users[username]['groups'] = new_groups
 
     def search(self, searchstring):
diff --git a/ldapcherry/backend/backendLdap.py b/ldapcherry/backend/backendLdap.py
index c36ba9f..5ac16e1 100644
--- a/ldapcherry/backend/backendLdap.py
+++ b/ldapcherry/backend/backendLdap.py
@@ -11,7 +11,10 @@ import ldap.modlist as modlist
 import ldap.filter
 import logging
 import ldapcherry.backend
-from sets import Set
+import sys
+if sys.version < '3':
+    from sets import Set as set
+
 from ldapcherry.exceptions import UserDoesntExist, \
     GroupDoesntExist, \
     UserAlreadyExists
@@ -74,12 +77,12 @@ class Backend(ldapcherry.backend.Backend):
         for o in re.split('\W+', self.get_param('objectclasses')):
             self.objectclasses.append(self._str(o))
         self.group_attrs = {}
-        self.group_attrs_keys = Set([])
+        self.group_attrs_keys = set([])
         for param in config:
             name, sep, group = param.partition('.')
             if name == 'group_attr':
                 self.group_attrs[group] = self.get_param(param)
-                self.group_attrs_keys |= Set(
+                self.group_attrs_keys |= set(
                     self._extract_format_keys(self.get_param(param))
                 )
 
@@ -393,7 +396,7 @@ class Backend(ldapcherry.backend.Backend):
         ldap_client.unbind_s()
 
     def set_attrs(self, username, attrs):
-        """ Set user attributes"""
+        """ set user attributes"""
         ldap_client = self._bind()
         tmp = self._get_user(self._str(username), ALL_ATTRS)
         if tmp is None:
diff --git a/ldapcherry/roles.py b/ldapcherry/roles.py
index 0bd1dd6..1c3bd91 100644
--- a/ldapcherry/roles.py
+++ b/ldapcherry/roles.py
@@ -9,7 +9,9 @@ import os
 import sys
 import copy
 
-from sets import Set
+if sys.version < '3':
+    from sets import Set as set
+
 from ldapcherry.pyyamlwrapper import loadNoDump
 from ldapcherry.pyyamlwrapper import DumplicatedKey
 from ldapcherry.exceptions import *
@@ -27,7 +29,7 @@ class Roles:
 
     def __init__(self, role_file):
         self.role_file = role_file
-        self.backends = Set([])
+        self.backends = set([])
         try:
             stream = open(role_file, 'r')
         except:
@@ -51,7 +53,7 @@ class Roles:
         for backends in backends_list:
             for b in backends:
                 if b not in ret:
-                    ret[b] = Set([])
+                    ret[b] = set([])
                 for group in backends[b]:
                     ret[b].add(group)
         for b in ret:
@@ -134,8 +136,8 @@ class Roles:
 
             if roleid not in self.graph:
                 self.graph[roleid] = {
-                    'parent_roles': Set([]),
-                    'sub_roles': Set([])
+                    'parent_roles': set([]),
+                    'sub_roles': set([])
                     }
 
         # Create the nested groups
@@ -147,7 +149,7 @@ class Roles:
                     if b not in self.group2roles:
                         self.group2roles[b] = {}
                     if g not in self.group2roles[b]:
-                        self.group2roles[b][g] = Set([])
+                        self.group2roles[b][g] = set([])
                     self.group2roles[b][g].add(roleid)
 
             parent_roles[roleid] = []
@@ -223,7 +225,7 @@ class Roles:
         # add groups of the role to usedgroups
         for b in self.roles[role]['backends_groups']:
             if b not in usedgroups:
-                usedgroups[b] = Set([])
+                usedgroups[b] = set([])
             for g in self.roles[role]['backends_groups'][b]:
                 usedgroups[b].add(g)
 
@@ -254,11 +256,11 @@ class Roles:
         """get groups to remove from list of
         roles to remove and current roles
         """
-        current_roles = Set(current_roles)
+        current_roles = set(current_roles)
 
         ret = {}
-        roles_to_remove = Set(roles_to_remove)
-        tmp = Set([])
+        roles_to_remove = set(roles_to_remove)
+        tmp = set([])
         # get sub roles of the role to remove that the user belongs to
         # if we remove a role, there is no reason to keep the sub roles
         for r in roles_to_remove:
@@ -267,7 +269,7 @@ class Roles:
                     tmp.add(sr)
 
         roles_to_remove = roles_to_remove.union(tmp)
-        roles = current_roles.difference(Set(roles_to_remove))
+        roles = current_roles.difference(set(roles_to_remove))
         groups_roles = self._get_groups(roles)
         groups_roles_to_remove = self._get_groups(roles_to_remove)
 
@@ -284,12 +286,12 @@ class Roles:
             for b in self.flatten[r]['backends_groups']:
                 groups = self.flatten[r]['backends_groups'][b]
                 if b not in ret:
-                    ret[b] = Set(groups)
-                ret[b] = ret[b].union(Set(groups))
+                    ret[b] = set(groups)
+                ret[b] = ret[b].union(set(groups))
         return ret
 
     def _get_subroles(self, role):
-        ret = Set([])
+        ret = set([])
         for sr in self.graph[role]['sub_roles']:
             tmp = self._get_subroles(sr)
             tmp.add(sr)
@@ -298,10 +300,10 @@ class Roles:
 
     def get_roles(self, groups):
         """get list of roles and list of standalone groups"""
-        roles = Set([])
-        parentroles = Set([])
-        notroles = Set([])
-        tmp = Set([])
+        roles = set([])
+        parentroles = set([])
+        notroles = set([])
+        tmp = set([])
         usedgroups = {}
         unusedgroups = {}
         ret = {}
@@ -316,7 +318,7 @@ class Roles:
             for g in groups[b]:
                 if b not in usedgroups or g not in usedgroups[b]:
                     if b not in unusedgroups:
-                        unusedgroups[b] = Set([])
+                        unusedgroups[b] = set([])
                     unusedgroups[b].add(g)
 
         ret['roles'] = roles