diff --git a/ldapcherry/__init__.py b/ldapcherry/__init__.py
index 2a6a15a..642ee2f 100644
--- a/ldapcherry/__init__.py
+++ b/ldapcherry/__init__.py
@@ -173,7 +173,7 @@ class LdapCherry(object):
             try:
                 self.backends_display_names[backend] = \
                     self.backends_params[backend]['display_name']
-            except:
+            except Exception as e:
                 self.backends_display_names[backend] = backend
                 self.backends_params[backend]['display_name'] = backend
             params = self.backends_params[backend]
@@ -225,7 +225,7 @@ class LdapCherry(object):
         )
         try:
             pp = __import__(module, globals(), locals(), ['PPolicy'], 0)
-        except:
+        except Exception as e:
             raise BackendModuleLoadingFail(module)
         if 'ppolicy' in config:
             ppcfg = config['ppolicy']
@@ -1091,7 +1091,7 @@ class LdapCherry(object):
         is_admin = self._check_admin()
         try:
             referer = cherrypy.request.headers['Referer']
-        except:
+        except Exception as e:
             referer = '/'
         self._deleteuser(user)
         self._add_notification('User Deleted')
@@ -1110,7 +1110,7 @@ class LdapCherry(object):
             self._add_notification("User modified")
             try:
                 referer = cherrypy.request.headers['Referer']
-            except:
+            except Exception as e:
                 referer = '/'
             raise cherrypy.HTTPRedirect(referer)
 
diff --git a/ldapcherry/attributes.py b/ldapcherry/attributes.py
index 75c863e..989bf14 100644
--- a/ldapcherry/attributes.py
+++ b/ldapcherry/attributes.py
@@ -33,7 +33,7 @@ class Attributes:
         self.key = None
         try:
             stream = open(attributes_file, 'r')
-        except:
+        except Exception as e:
             raise MissingAttributesFile(attributes_file)
         try:
             self.attributes = loadNoDump(stream)
@@ -71,7 +71,7 @@ class Attributes:
             raise MissingUserKey()
 
     def _is_email(self, email):
-        pattern = '[\.\w]{1,}[@]\w+[.]\w+'
+        pattern = r'[\.\w]{1,}[@]\w+[.]\w+'
         if re.match(pattern, email):
             return True
         else:
diff --git a/ldapcherry/backend/backendDemo.py b/ldapcherry/backend/backendDemo.py
index 0377bad..6e0e0b4 100644
--- a/ldapcherry/backend/backendDemo.py
+++ b/ldapcherry/backend/backendDemo.py
@@ -9,14 +9,13 @@
 
 
 import sys
-if sys.version < '3':
-    from sets import Set as set
-
 import ldapcherry.backend
 from ldapcherry.exceptions import UserDoesntExist, \
     GroupDoesntExist, MissingParameter, \
     UserAlreadyExists
 import re
+if sys.version < '3':
+    from sets import Set as set
 
 
 class Backend(ldapcherry.backend.Backend):
@@ -41,13 +40,17 @@ 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(self._basic_splitter(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(self._basic_splitter(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(
-            re.split('\W+', self.get_param('search_attributes')),
+            re.split(r'\W+', self.get_param('search_attributes')),
             )
         self.pwd_attr = pwd_attr
         self.admin_user = admin_user
@@ -66,7 +69,8 @@ class Backend(ldapcherry.backend.Backend):
 
     @staticmethod
     def _basic_splitter(in_str):
-        return [re.sub(r'(?<!\\)\\', '', x) for x in re.split(r'(?<!\\),\W*', 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:
@@ -111,7 +115,7 @@ class Backend(ldapcherry.backend.Backend):
         self._check_fix_users(username)
         try:
             del self.users[username]
-        except:
+        except Exception as e:
             raise UserDoesntExist(username, self.backend_name)
 
     def set_attrs(self, username, attrs):
@@ -184,7 +188,7 @@ class Backend(ldapcherry.backend.Backend):
         """
         try:
             return self.users[username]
-        except:
+        except Exception as e:
             raise UserDoesntExist(username, self.backend_name)
 
     def get_groups(self, username):
@@ -196,5 +200,5 @@ class Backend(ldapcherry.backend.Backend):
         """
         try:
             return self.users[username]['groups']
-        except:
+        except Exception as e:
             raise UserDoesntExist(username, self.backend_name)
diff --git a/ldapcherry/backend/backendLdap.py b/ldapcherry/backend/backendLdap.py
index 5ac16e1..9bf177c 100644
--- a/ldapcherry/backend/backendLdap.py
+++ b/ldapcherry/backend/backendLdap.py
@@ -12,14 +12,13 @@ import ldap.filter
 import logging
 import ldapcherry.backend
 import sys
-if sys.version < '3':
-    from sets import Set as set
-
 from ldapcherry.exceptions import UserDoesntExist, \
     GroupDoesntExist, \
     UserAlreadyExists
 import os
 import re
+if sys.version < '3':
+    from sets import Set as set
 
 
 class CaFileDontExist(Exception):
@@ -74,7 +73,7 @@ class Backend(ldapcherry.backend.Backend):
         self.key = key
         # objectclasses parameter is a coma separated list in configuration
         # split it to get a real list, and convert it to bytes
-        for o in re.split('\W+', self.get_param('objectclasses')):
+        for o in re.split(r'\W+', self.get_param('objectclasses')):
             self.objectclasses.append(self._str(o))
         self.group_attrs = {}
         self.group_attrs_keys = set([])
diff --git a/ldapcherry/roles.py b/ldapcherry/roles.py
index 1c3bd91..9fc6a92 100644
--- a/ldapcherry/roles.py
+++ b/ldapcherry/roles.py
@@ -9,14 +9,14 @@ import os
 import sys
 import copy
 
-if sys.version < '3':
-    from sets import Set as set
-
 from ldapcherry.pyyamlwrapper import loadNoDump
 from ldapcherry.pyyamlwrapper import DumplicatedKey
 from ldapcherry.exceptions import *
 import yaml
 
+if sys.version < '3':
+    from sets import Set as set
+
 
 class CustomDumper(yaml.SafeDumper):
     "A custom YAML dumper that never emits aliases"
@@ -32,7 +32,7 @@ class Roles:
         self.backends = set([])
         try:
             stream = open(role_file, 'r')
-        except:
+        except Exception as e:
             raise MissingRolesFile(role_file)
         try:
             self.roles_raw = loadNoDump(stream)