diff --git a/plugins/dbus_plugin/plugin.py b/plugins/dbus_plugin/plugin.py
index b8de568e9..a3dcae62e 100644
--- a/plugins/dbus_plugin/plugin.py
+++ b/plugins/dbus_plugin/plugin.py
@@ -508,7 +508,7 @@ if dbus_support.supported:
             def prefs_store(self):
                 try:
                     gajim.interface.save_config()
-                except Exception as e:
+                except Exception:
                     return DBUS_BOOLEAN(False)
                 return DBUS_BOOLEAN(True)
 
diff --git a/src/common/connection_handlers_events.py b/src/common/connection_handlers_events.py
index a41929993..412e31e73 100644
--- a/src/common/connection_handlers_events.py
+++ b/src/common/connection_handlers_events.py
@@ -218,7 +218,7 @@ class TimeResultReceivedEvent(nec.NetworkIncomingEvent, HelperEvent):
 
         try:
             t = datetime.datetime.strptime(utc_time, '%Y-%m-%dT%H:%M:%SZ')
-        except ValueError as e:
+        except ValueError:
             try:
                 t = datetime.datetime.strptime(utc_time,
                     '%Y-%m-%dT%H:%M:%S.%fZ')
diff --git a/src/common/contacts.py b/src/common/contacts.py
index 3d411bf24..83d42f436 100644
--- a/src/common/contacts.py
+++ b/src/common/contacts.py
@@ -36,7 +36,7 @@ try:
     import common.gajim
 except ImportError as e:
     if __name__ != "__main__":
-        raise ImportError(e)
+        raise ImportError(str(e))
 
 class XMPPEntity(object):
     """
diff --git a/src/common/ged.py b/src/common/ged.py
index d46214fc5..79b5b3e95 100644
--- a/src/common/ged.py
+++ b/src/common/ged.py
@@ -79,7 +79,7 @@ class GlobalEventsDispatcher(object):
         if event_name in self.handlers:
             try:
                 self.handlers[event_name].remove((priority, handler))
-            except ValueError as error:
+            except ValueError:
                 log.warn('''Function (%s) with priority "%s" never registered
                 as handler of event "%s". Couldn\'t remove. Error: %s'''
                                   %(handler, priority, event_name, error))
@@ -94,7 +94,7 @@ class GlobalEventsDispatcher(object):
                         return True
                 except NodeProcessed:
                     node_processed = True
-                except Exception as e:
+                except Exception:
                     log.error('Error while running an even handler: %s' % \
                         handler)
                     traceback.print_exc()
diff --git a/src/common/helpers.py b/src/common/helpers.py
index d648a3367..791935aa5 100644
--- a/src/common/helpers.py
+++ b/src/common/helpers.py
@@ -915,7 +915,8 @@ def get_auth_sha(sid, initiator, target):
     """
     Return sha of sid + initiator + target used for proxy auth
     """
-    return hashlib.sha1("%s%s%s" % (sid, initiator, target)).hexdigest()
+    return hashlib.sha1(("%s%s%s" % (sid, initiator, target)).encode('utf-8')).\
+        hexdigest()
 
 def remove_invalid_xml_chars(string):
     if string:
@@ -1545,9 +1546,9 @@ def _get_img_proxy(attrs, proxy):
         alt = attrs.get('alt', '')
         if alt:
             alt += '\n'
-        if ex[0] == pycurl.E_FILESIZE_EXCEEDED:
+        if ex.errno == pycurl.E_FILESIZE_EXCEEDED:
             alt += _('Image is too big')
-        elif ex[0] == pycurl.E_OPERATION_TIMEOUTED:
+        elif ex.errno == pycurl.E_OPERATION_TIMEOUTED:
             alt += _('Timeout loading image')
         else:
             alt += _('Error loading image')
diff --git a/src/common/idle.py b/src/common/idle.py
index c2cccdd4b..9e475c47d 100644
--- a/src/common/idle.py
+++ b/src/common/idle.py
@@ -68,7 +68,7 @@ try:
 
     rootwindow = libX11.XDefaultRootWindow(dpy_p)
     xss_available = True
-except OSError as e:
+except OSError:
     # Logging?
     xss_available = False
 
diff --git a/src/common/jingle_ft.py b/src/common/jingle_ft.py
index c050cf6b3..c7636d3d1 100644
--- a/src/common/jingle_ft.py
+++ b/src/common/jingle_ft.py
@@ -95,8 +95,8 @@ class JingleFileTransfer(JingleContent):
         if gajim.contacts.is_gc_contact(session.connection.name,
         session.peerjid):
             roomjid = session.peerjid.split('/')[0]
-            dstaddr = hashlib.sha1('%s%s%s' % (self.file_props['sid'],
-                session.ourjid, roomjid)).hexdigest()
+            dstaddr = hashlib.sha1(('%s%s%s' % (self.file_props['sid'],
+                session.ourjid, roomjid)).encode('utf-8')).hexdigest()
             self.file_props.dstaddr = dstaddr
         self.state = STATE_NOT_STARTED
         self.states = {STATE_INITIALIZED   : StateInitialized(self),
diff --git a/src/common/jingle_rtp.py b/src/common/jingle_rtp.py
index 3897e48cc..497f7e216 100644
--- a/src/common/jingle_rtp.py
+++ b/src/common/jingle_rtp.py
@@ -105,13 +105,13 @@ class JingleRTPContent(JingleContent):
         try:
             bin = gst.parse_bin_from_description(pipeline, True)
             return bin
-        except GError as error_str:
+        except GError as e:
             gajim.nec.push_incoming_event(InformationEvent(None,
                 conn=self.session.connection, level='error',
                 pri_txt=_('%s configuration error') % text.capitalize(),
                 sec_txt=_("Couldn't setup %s. Check your configuration.\n\n"
                 "Pipeline was:\n%s\n\nError was:\n%s") % (text, pipeline,
-                error_str)))
+                str(e))))
             raise JingleContentSetupException
 
     def add_remote_candidates(self, candidates):
diff --git a/src/common/logger.py b/src/common/logger.py
index 3ce6fab62..69745c7e7 100644
--- a/src/common/logger.py
+++ b/src/common/logger.py
@@ -256,7 +256,7 @@ class Logger:
             self.cur.execute('INSERT INTO jids (jid, type) VALUES (?, ?)', (jid,
                     typ))
             self.con.commit()
-        except sqlite.IntegrityError as e:
+        except sqlite.IntegrityError:
             # Jid already in DB, maybe added by another instance. re-read DB
             self.get_jids_already_in_db()
             return self.get_jid_id(jid, typestr)
@@ -580,7 +580,7 @@ class Logger:
         """
         try:
             self.get_jid_id(jid)
-        except exceptions.PysqliteOperationalError as e:
+        except exceptions.PysqliteOperationalError:
             # Error trying to create a new jid_id. This means there is no log
             return []
         where_sql, jid_tuple = self._build_contact_where(account, jid)
@@ -624,7 +624,7 @@ class Logger:
         """
         try:
             self.get_jid_id(jid)
-        except exceptions.PysqliteOperationalError as e:
+        except exceptions.PysqliteOperationalError:
             # Error trying to create a new jid_id. This means there is no log
             return []
         where_sql, jid_tuple = self._build_contact_where(account, jid)
@@ -653,7 +653,7 @@ class Logger:
         """
         try:
             self.get_jid_id(jid)
-        except exceptions.PysqliteOperationalError as e:
+        except exceptions.PysqliteOperationalError:
             # Error trying to create a new jid_id. This means there is no log
             return []
 
@@ -694,7 +694,7 @@ class Logger:
         """
         try:
             self.get_jid_id(jid)
-        except exceptions.PysqliteOperationalError as e:
+        except exceptions.PysqliteOperationalError:
             # Error trying to create a new jid_id. This means there is no log
             return []
         days_with_logs = []
@@ -736,7 +736,7 @@ class Logger:
         else:
             try:
                 jid_id = self.get_jid_id(jid, 'ROOM')
-            except exceptions.PysqliteOperationalError as e:
+            except exceptions.PysqliteOperationalError:
                 # Error trying to create a new jid_id. This means there is no log
                 return None
             where_sql = 'jid_id = ?'
@@ -762,7 +762,7 @@ class Logger:
         """
         try:
             jid_id = self.get_jid_id(jid, 'ROOM')
-        except exceptions.PysqliteOperationalError as e:
+        except exceptions.PysqliteOperationalError:
             # Error trying to create a new jid_id. This means there is no log
             return None
         where_sql = 'jid_id = %s' % jid_id
@@ -802,7 +802,7 @@ class Logger:
             for user in family:
                 try:
                     jid_id = self.get_jid_id(user['jid'])
-                except exceptions.PysqliteOperationalError as e:
+                except exceptions.PysqliteOperationalError:
                     continue
                 where_sql += 'jid_id = ?'
                 jid_tuple += (jid_id,)
diff --git a/src/common/optparser.py b/src/common/optparser.py
index 520bd94d0..95f59c674 100644
--- a/src/common/optparser.py
+++ b/src/common/optparser.py
@@ -644,7 +644,7 @@ class OptionsParser:
                     '''
             )
             con.commit()
-        except sqlite.OperationalError as e:
+        except sqlite.OperationalError:
             pass
         con.close()
         gajim.config.set('version', '0.11.4.4')
diff --git a/src/common/proxy65_manager.py b/src/common/proxy65_manager.py
index db81598dd..1d0fe6486 100644
--- a/src/common/proxy65_manager.py
+++ b/src/common/proxy65_manager.py
@@ -310,7 +310,7 @@ class HostTester(Socks5, IdleObject):
             # read auth response
             if buff is None or len(buff) != 2:
                 return None
-            version, method = struct.unpack('!BB', buff[:2])
+            version, method = struct.unpack('!BB', buff[:2].encode('utf-8'))
             if version != 0x05 or method == 0xff:
                 self.pollend()
                 return
@@ -334,7 +334,7 @@ class HostTester(Socks5, IdleObject):
             self._send = self._sock.send
             self._recv = self._sock.recv
         except Exception as ee:
-            errnum = ee[0]
+            errnum = ee.errno
             # 56 is for freebsd
             if errnum in (errno.EINPROGRESS, errno.EALREADY, errno.EWOULDBLOCK):
                 # still trying to connect
@@ -431,7 +431,7 @@ class ReceiverTester(Socks5, IdleObject):
             # read auth response
             if buff is None or len(buff) != 2:
                 return None
-            version, method = struct.unpack('!BB', buff[:2])
+            version, method = struct.unpack('!BB', buff[:2].encode('utf-8'))
             if version != 0x05 or method == 0xff:
                 self.pollend()
                 return
@@ -443,7 +443,7 @@ class ReceiverTester(Socks5, IdleObject):
             # read connect response
             if buff is None or len(buff) < 2:
                 return None
-            version, reply = struct.unpack('!BB', buff[:2])
+            version, reply = struct.unpack('!BB', buff[:2].encode('utf-8'))
             if version != 0x05 or reply != 0x00:
                 self.pollend()
                 return
diff --git a/src/common/socks5.py b/src/common/socks5.py
index c57be17a5..c9768f3e7 100644
--- a/src/common/socks5.py
+++ b/src/common/socks5.py
@@ -464,7 +464,7 @@ class Socks5:
                 self._server = ai[4]
                 break
             except socket.error as e:
-                if not isinstance(e, basestring) and e[0] == EINPROGRESS:
+                if e.errno == EINPROGRESS:
                     break
                 # for all other errors, we try other addresses
                 continue
@@ -482,7 +482,7 @@ class Socks5:
             self._send=self._sock.send
             self._recv=self._sock.recv
         except Exception as ee:
-            errnum = ee[0]
+            errnum = ee.errno
             self.connect_timeout += 1
             if errnum == 111 or self.connect_timeout > 1000:
                 self.queue._connection_refused(self.streamhost, self.file_props,
@@ -581,7 +581,7 @@ class Socks5:
         """
         received = ''
         try:
-            add = self._recv(64)
+            add = self._recv(64).decode('utf-8')
         except (OpenSSL.SSL.WantReadError, OpenSSL.SSL.WantWriteError,
         OpenSSL.SSL.WantX509LookupError) as e:
             log.info('SSL rehandshake request : ' + repr(e))
@@ -603,7 +603,7 @@ class Socks5:
         OpenSSL.SSL.WantX509LookupError) as e:
             log.info('SSL rehandshake request :' + repr(e))
             raise e
-        except Exception as e:
+        except Exception:
             self.disconnect()
         return len(raw_data)
 
@@ -614,7 +614,7 @@ class Socks5:
         else:
             try:
                 self.open_file_for_reading()
-            except IOError as e:
+            except IOError:
                 self.state = 8 # end connection
                 self.disconnect()
                 self.file_props.error = -7 # unable to read from file
@@ -629,7 +629,7 @@ class Socks5:
                 log.info('SSL rehandshake request :' + repr(e))
                 raise e
             except Exception as e:
-                if e.args[0] not in (EINTR, ENOBUFS, EWOULDBLOCK):
+                if e.errno not in (EINTR, ENOBUFS, EWOULDBLOCK):
                     # peer stopped reading
                     self.state = 8 # end connection
                     self.disconnect()
@@ -671,7 +671,7 @@ class Socks5:
         if self.remaining_buff != '':
             try:
                 fd = self.get_fd()
-            except IOError as e:
+            except IOError:
                 self.disconnect(False)
                 self.file_props.error = -6 # file system error
                 return 0
@@ -692,12 +692,12 @@ class Socks5:
         else:
             try:
                 fd = self.get_fd()
-            except IOError as e:
+            except IOError:
                 self.disconnect(False)
                 self.file_props.error = -6 # file system error
                 return 0
             try:
-                buff = self._recv(MAX_BUFF_LEN)
+                buff = self._recv(MAX_BUFF_LEN).decode('utf-8')
             except (OpenSSL.SSL.WantReadError, OpenSSL.SSL.WantWriteError,
             OpenSSL.SSL.WantX509LookupError) as e:
                 log.info('SSL rehandshake request :' + repr(e))
@@ -718,7 +718,7 @@ class Socks5:
                 return 0
             try:
                 fd.write(buff)
-            except IOError as e:
+            except IOError:
                 self.rem_fd(fd)
                 self.disconnect()
                 self.file_props.error = -6 # file system error
@@ -780,9 +780,9 @@ class Socks5:
         """
         auth_mechanisms = []
         try:
-            num_auth = struct.unpack('!xB', buff[:2])[0]
+            num_auth = struct.unpack('!xB', buff[:2].encode('utf-8'))[0]
             for i in list(range(num_auth)):
-                mechanism, = struct.unpack('!B', buff[1 + i])
+                mechanism, = struct.unpack('!B', buff[1 + i].encode('utf-8'))
                 auth_mechanisms.append(mechanism)
         except Exception:
             return None
@@ -799,8 +799,8 @@ class Socks5:
         Connect request by domain name
         """
         buff = struct.pack('!BBBBB%dsBB' % len(self.host),
-            0x05, 0x01, 0x00, 0x03, len(self.host), self.host, self.port >> 8,
-            self.port & 0xff)
+            0x05, 0x01, 0x00, 0x03, len(self.host), self.host.encode('utf-8'),
+            self.port >> 8, self.port & 0xff)
         return buff
 
     def _get_request_buff(self, msg, command = 0x01):
@@ -809,27 +809,30 @@ class Socks5:
         0096)
         """
         buff = struct.pack('!BBBBB%dsBB' % len(msg),
-                0x05, command, 0x00, 0x03, len(msg), msg, 0, 0)
+            0x05, command, 0x00, 0x03, len(msg), msg.encode('utf-8'), 0, 0)
         return buff
 
     def _parse_request_buff(self, buff):
         try: # don't trust on what comes from the outside
-            req_type, host_type, = struct.unpack('!xBxB', buff[:4])
+            req_type, host_type, = struct.unpack('!xBxB', buff[:4].encode(
+                'utf-8'))
             if host_type == 0x01:
-                host_arr = struct.unpack('!iiii', buff[4:8])
+                host_arr = struct.unpack('!iiii', buff[4:8].encode('utf-8'))
                 host, = '.'.join(str(s) for s in host_arr)
                 host_len = len(host)
             elif host_type == 0x03:
-                host_len,  = struct.unpack('!B', buff[4])
-                host, = struct.unpack('!%ds' % host_len, buff[5:5 + host_len])
+                host_len,  = struct.unpack('!B', buff[4].encode('utf-8'))
+                host, = struct.unpack('!%ds' % host_len, buff[5:5 + host_len].\
+                    encode('utf-8'))
             portlen = len(buff[host_len + 5:])
             if portlen == 1:
-                port, = struct.unpack('!B', buff[host_len + 5])
+                port, = struct.unpack('!B', buff[host_len + 5].encode('utf-8'))
             elif portlen == 2:
-                port, = struct.unpack('!H', buff[host_len + 5:])
+                port, = struct.unpack('!H', buff[host_len + 5:].encode('utf-8'))
             # file data, comes with auth message (Gaim bug)
             else:
-                port, = struct.unpack('!H', buff[host_len + 5: host_len + 7])
+                port, = struct.unpack('!H', buff[host_len + 5: host_len + 7].\
+                    encode('utf-8'))
                 self.remaining_buff = buff[host_len + 7:]
         except Exception:
             return (None, None, None)
@@ -840,13 +843,13 @@ class Socks5:
         Connect response: version, auth method
         """
         try:
-            buff = self._recv()
+            buff = self._recv().decode('utf-8')
         except (SSL.WantReadError, SSL.WantWriteError,
         SSL.WantX509LookupError) as e:
             log.info("SSL rehandshake request : " + repr(e))
             raise e
         try:
-            version, method = struct.unpack('!BB', buff)
+            version, method = struct.unpack('!BB', buff.encode('utf-8'))
         except Exception:
             version, method = None, None
         if version != 0x05 or method == 0xff:
@@ -864,8 +867,8 @@ class Socks5:
         """
         Get sha of sid + Initiator jid + Target jid
         """
-        return hashlib.sha1('%s%s%s' % (self.sid, self.initiator,
-            self.target)).hexdigest()
+        return hashlib.sha1(('%s%s%s' % (self.sid, self.initiator,
+            self.target)).encode('utf-8')).hexdigest()
 
 
 class Socks5Sender(IdleObject):
@@ -1151,7 +1154,7 @@ class Socks5Client(Socks5):
         if self.state == 2: # read auth response
             if buff is None or len(buff) != 2:
                 return None
-            version, method = struct.unpack('!BB', buff[:2])
+            version, method = struct.unpack('!BB', buff[:2].encode('utf-8'))
             if version != 0x05 or method == 0xff:
                 self.disconnect()
         elif self.state == 4: # get approve of our request
@@ -1160,18 +1163,23 @@ class Socks5Client(Socks5):
             sub_buff = buff[:4]
             if len(sub_buff) < 4:
                 return None
-            version, address_type = struct.unpack('!BxxB', buff[:4])
+            version, address_type = struct.unpack('!BxxB', buff[:4].encode(
+                'utf-8'))
             addrlen = 0
             if address_type == 0x03:
                 addrlen = ord(buff[4])
-                address = struct.unpack('!%ds' % addrlen, buff[5:addrlen + 5])
+                address = struct.unpack('!%ds' % addrlen, buff[5:addrlen + 5].\
+                    encode('utf-8'))
                 portlen = len(buff[addrlen + 5:])
                 if portlen == 1:
-                    port, = struct.unpack('!B', buff[addrlen + 5])
+                    port, = struct.unpack('!B', buff[addrlen + 5].encode(
+                        'utf-8'))
                 elif portlen == 2:
-                    port, = struct.unpack('!H', buff[addrlen + 5:])
+                    port, = struct.unpack('!H', buff[addrlen + 5:].encode(
+                        'utf-8'))
                 else: # Gaim bug :)
-                    port, = struct.unpack('!H', buff[addrlen + 5:addrlen + 7])
+                    port, = struct.unpack('!H', buff[addrlen + 5:addrlen + 7].\
+                        encode('utf-8'))
                     self.remaining_buff = buff[addrlen + 7:]
             self.state = 5 # for senders: init file_props and send '\n'
             if self.queue.on_success:
@@ -1347,7 +1355,7 @@ class Socks5Listener(IdleObject):
                     self._serv = OpenSSL.SSL.Connection(
                         jingle_xtls.get_context('server'), self._serv)
             except socket.error as e:
-                if e.args[0] == EAFNOSUPPORT:
+                if e.errno == EAFNOSUPPORT:
                     self.ai = None
                     continue
                 raise
diff --git a/src/common/zeroconf/client_zeroconf.py b/src/common/zeroconf/client_zeroconf.py
index 3d5b43f43..07f82092a 100644
--- a/src/common/zeroconf/client_zeroconf.py
+++ b/src/common/zeroconf/client_zeroconf.py
@@ -357,8 +357,8 @@ class P2PConnection(IdleObject, PlugIn):
                 self.ais = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
                         socket.SOCK_STREAM)
             except socket.gaierror as e:
-                log.info('Lookup failure for %s: %s[%s]', host, e[1],
-                    repr(e[0]), exc_info=True)
+                log.info('Lookup failure for %s: %s', host, str(e),
+                    exc_info=True)
             else:
                 self.connect_to_next_ip()
 
@@ -449,7 +449,8 @@ class P2PConnection(IdleObject, PlugIn):
             self._sock.connect(self._server)
             self._sock.setblocking(False)
         except Exception as ee:
-            (errnum, errstr) = ee
+            errnum = ee.errno
+            errstr = ee.strerror
         errors = (errno.EINPROGRESS, errno.EALREADY, errno.EWOULDBLOCK)
         if 'WSAEINVAL' in errno.__dict__:
             errors += (errno.WSAEINVAL,)
@@ -489,8 +490,7 @@ class P2PConnection(IdleObject, PlugIn):
             # get as many bites, as possible, but not more than RECV_BUFSIZE
             received = self._sock.recv(MAX_BUFF_LEN)
         except Exception as e:
-            if len(e.args) > 0 and isinstance(e.args[0], int):
-                errnum = e[0]
+            errnum = e.errno
             # "received" will be empty anyhow
         if errnum == socket.SSL_ERROR_WANT_READ:
             pass
@@ -560,7 +560,7 @@ class P2PConnection(IdleObject, PlugIn):
                 self._on_send()
 
         except socket.error as e:
-            if e[0] == socket.SSL_ERROR_WANT_WRITE:
+            if e.errno == socket.SSL_ERROR_WANT_WRITE:
                 return True
             if self.state < 0:
                 self.disconnect()
diff --git a/src/common/zeroconf/zeroconf_avahi.py b/src/common/zeroconf/zeroconf_avahi.py
index 73f091928..e2a7c1fd4 100644
--- a/src/common/zeroconf/zeroconf_avahi.py
+++ b/src/common/zeroconf/zeroconf_avahi.py
@@ -22,7 +22,7 @@ log = logging.getLogger('gajim.c.z.zeroconf_avahi')
 
 try:
     import dbus.exceptions
-except ImportError as e:
+except ImportError:
     pass
 
 from common.zeroconf.zeroconf import C_BARE_NAME, C_INTERFACE, C_PROTOCOL, C_DOMAIN
diff --git a/src/common/zeroconf/zeroconf_bonjour.py b/src/common/zeroconf/zeroconf_bonjour.py
index 7d1566e34..593fa95b0 100644
--- a/src/common/zeroconf/zeroconf_bonjour.py
+++ b/src/common/zeroconf/zeroconf_bonjour.py
@@ -24,7 +24,7 @@ from common.zeroconf.zeroconf import C_BARE_NAME, C_DOMAIN
 
 try:
     import pybonjour
-except ImportError as e:
+except ImportError:
     pass
 
 
@@ -283,7 +283,7 @@ class Zeroconf:
         try:
             self.browse_sdRef = pybonjour.DNSServiceBrowse(regtype=self.stype, domain=domain, callBack=self.browse_callback)
         except pybonjour.BonjourError as e:
-            self.error_CB("Error while browsing: %s" % e)
+            self.error_CB("Error while browsing: %s" % str(e))
 
     def browse_loop(self):
         ready = select.select([self.browse_sdRef], [], [], 0)
diff --git a/src/config.py b/src/config.py
index 597c74876..fadc0f1ba 100644
--- a/src/config.py
+++ b/src/config.py
@@ -3385,7 +3385,7 @@ class ManageBookmarksWindow:
             nick = self.nick_entry.get_text()
             try:
                 nick = helpers.parse_resource(nick)
-            except helpers.InvalidFormat as e:
+            except helpers.InvalidFormat:
                 dialogs.ErrorDialog(_('Invalid nickname'),
                         _('Character not allowed'))
                 self.nick_entry.set_text(model[iter_][6])
@@ -3424,7 +3424,7 @@ class ManageBookmarksWindow:
             self.server_entry.get_text().strip()
         try:
             room_jid = helpers.parse_resource(room_jid)
-        except helpers.InvalidFormat as e:
+        except helpers.InvalidFormat:
             dialogs.ErrorDialog(_('Invalid room'),
                     _('Character not allowed'))
             self.room_entry.set_text(model[iter_][2].split('@')[0])
diff --git a/src/dialogs.py b/src/dialogs.py
index 1f705a344..17ecd19e7 100644
--- a/src/dialogs.py
+++ b/src/dialogs.py
@@ -2755,7 +2755,7 @@ class NewChatDialog(InputDialog):
             try:
                 jid = helpers.parse_jid(jid)
             except helpers.InvalidFormat as e:
-                ErrorDialog(_('Invalid JID'), e[0])
+                ErrorDialog(_('Invalid JID'), str(e))
                 return
             except:
                 ErrorDialog(_('Invalid JID'), _('Unable to parse "%s".') % jid)
diff --git a/src/gajim.py b/src/gajim.py
index be2a01d00..d6ffabff4 100644
--- a/src/gajim.py
+++ b/src/gajim.py
@@ -132,7 +132,7 @@ def parseOpts():
         longargs += ' sm-client-id= sm-client-state-file= sm-disable'
         opts = getopt.getopt(sys.argv[1:], shortargs, longargs.split())[0]
     except getopt.error as msg1:
-        print(msg1)
+        print(str(msg1))
         print('for help use --help')
         sys.exit(2)
     for o, a in opts:
diff --git a/src/gtkgui_helpers.py b/src/gtkgui_helpers.py
index 8b29f2065..5f236ae86 100644
--- a/src/gtkgui_helpers.py
+++ b/src/gtkgui_helpers.py
@@ -349,10 +349,10 @@ def parse_server_xml(path_to_file):
         return handler.servers
     # handle exception if unable to open file
     except IOError as message:
-        print(_('Error reading file:') + message, file=sys.stderr)
+        print(_('Error reading file:') + str(message), file=sys.stderr)
     # handle exception parsing file
     except xml.sax.SAXParseException as message:
-        print(_('Error parsing file:') + message, file=sys.stderr)
+        print(_('Error parsing file:') + str(message), file=sys.stderr)
 
 def set_unset_urgency_hint(window, unread_messages_no):
     """
diff --git a/src/htmltextview.py b/src/htmltextview.py
index d52ef21e3..df9557be2 100644
--- a/src/htmltextview.py
+++ b/src/htmltextview.py
@@ -766,7 +766,7 @@ class HtmlHandler(xml.sax.handler.ContentHandler):
                 #self._insert_text('\u2550'*40)
                 self._jump_line()
             except Exception as e:
-                log.debug(str('Error in hr'+e))
+                log.debug('Error in hr' + str(e))
         elif name in LIST_ELEMS:
             self.list_counters.pop()
         elif name == 'li':
diff --git a/src/plugins/pluginmanager.py b/src/plugins/pluginmanager.py
index 71c0c2e61..ed8a9d366 100644
--- a/src/plugins/pluginmanager.py
+++ b/src/plugins/pluginmanager.py
@@ -427,9 +427,9 @@ class PluginManager(object):
                 try:
                     module = __import__(module_name)
                 except ValueError as value_error:
-                    log.debug(value_error)
+                    log.debug(str(value_error))
                 except ImportError as import_error:
-                    log.debug(import_error)
+                    log.debug(str(import_error))
 
             elif os.path.isdir(file_path) and scan_dirs:
                 module_name = elem_name
@@ -440,9 +440,9 @@ class PluginManager(object):
                 try:
                     module = __import__(module_name)
                 except ValueError as value_error:
-                    log.debug(value_error)
+                    log.debug(str(value_error))
                 except ImportError as import_error:
-                    log.debug(import_error)
+                    log.debug(str(import_error))
 
 
             if module is None:
@@ -477,21 +477,21 @@ class PluginManager(object):
 
                     plugins_found.append(module_attr)
 
-                except TypeError as type_error:
+                except TypeError:
                     # set plugin localization
                     try:
                         module_attr._ = _
-                    except AttributeError as type_error:
+                    except AttributeError:
                         pass
-                except configparser.NoOptionError as type_error:
+                except configparser.NoOptionError:
                     # all fields are required
                     log.debug('%s : %s' % (module_attr_name,
                         'wrong manifest file. all fields are required!'))
-                except configparser.NoSectionError as type_error:
+                except configparser.NoSectionError:
                     # info section are required
                     log.debug('%s : %s' % (module_attr_name,
                         'wrong manifest file. info section are required!'))
-                except configparser.MissingSectionHeaderError as type_error:
+                except configparser.MissingSectionHeaderError:
                     # info section are required
                     log.debug('%s : %s' % (module_attr_name,
                         'wrong manifest file. section are required!'))
@@ -504,10 +504,10 @@ class PluginManager(object):
         '''
         try:
             zip_file = zipfile.ZipFile(zip_filename)
-        except zipfile.BadZipfile as e:
+        except zipfile.BadZipfile:
             # it is not zip file
             raise PluginsystemError(_('Archive corrupted'))
-        except IOError as e:
+        except IOError:
             raise PluginsystemError(_('Archive empty'))
 
         if zip_file.testzip():
diff --git a/src/plugins/plugins_i18n.py b/src/plugins/plugins_i18n.py
index 9eb983eff..91ee811dc 100644
--- a/src/plugins/plugins_i18n.py
+++ b/src/plugins/plugins_i18n.py
@@ -36,6 +36,6 @@ if os.name != 'nt':
 try:
     t = gettext.translation(APP, plugins_locale_dir)
     _ = t.gettext
-except IOError as msg:
+except IOError:
     from common import i18n
     _ = gettext.gettext
diff --git a/src/remote_control.py b/src/remote_control.py
index da7e50015..e91eebe99 100644
--- a/src/remote_control.py
+++ b/src/remote_control.py
@@ -743,7 +743,7 @@ class SignalObject(dbus.service.Object):
     def prefs_store(self):
         try:
             gajim.interface.save_config()
-        except Exception as e:
+        except Exception:
             return DBUS_BOOLEAN(False)
         return DBUS_BOOLEAN(True)
 
diff --git a/test/unit/test_socks5.py b/test/unit/test_socks5.py
index 86f46d033..f137d7aed 100644
--- a/test/unit/test_socks5.py
+++ b/test/unit/test_socks5.py
@@ -15,24 +15,21 @@ from common import jingle_xtls
 
 class fake_sock(Mock):
     def __init__(self, sockobj):
-         Mock.__init__(self)
+        Mock.__init__(self)
 
-         self.sockobj = sockobj
+        self.sockobj = sockobj
 
 
     def setup_stream(self):
-         sha1 = self.sockobj._get_sha1_auth()
+        sha1 = self.sockobj._get_sha1_auth()
+
+        self.incoming = []
+        self.incoming.append(self.sockobj._get_auth_response())
+        self.incoming.append(self.sockobj._get_request_buff(sha1, 0x00))
+        self.outgoing = []
+        self.outgoing.append(self.sockobj._get_auth_buff())
+        self.outgoing.append(self.sockobj._get_request_buff(sha1))
 
-         self.incoming = []
-         self.incoming.append(self.sockobj._get_auth_response())
-         self.incoming.append(
-                self.sockobj._get_request_buff(sha1, 0x00)
-                             )
-         self.outgoing = []
-         self.outgoing.append(self.sockobj._get_auth_buff())
-         self.outgoing.append(self.sockobj._get_request_buff(
-                                                sha1
-                                                       ))
     def switch_stream(self):
         # Roles are reversed, client will be expecting server stream
         # and server will be expecting client stream