diff --git a/src/common.py b/src/common.py
index 0940757e..03c9b6a4 100644
--- a/src/common.py
+++ b/src/common.py
@@ -39,7 +39,6 @@ import mimetypes
 import hashlib
 import subprocess
 import curses
-import sys
 import time
 import shlex
 
diff --git a/src/core.py b/src/core.py
index aeb06adf..d113fe25 100644
--- a/src/core.py
+++ b/src/core.py
@@ -14,8 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with Poezio.  If not, see <http://www.gnu.org/licenses/>.
 
-from gettext import (bindtextdomain, textdomain, bind_textdomain_codeset,
-                     gettext as _)
+from gettext import gettext as _
 
 from time import sleep
 
@@ -238,7 +237,7 @@ class Core(object):
         elif message['type'] == 'groupchat':
             self.on_chatstate_groupchat_conversation(message, state)
 
-    def on_chatstate_normal_conversation(self, message,state):
+    def on_chatstate_normal_conversation(self, message, state):
         tab = self.get_tab_of_conversation_with_jid(message['from'], False)
         if not tab:
             return False
diff --git a/src/data_forms.py b/src/data_forms.py
index 35377fd6..a014365a 100644
--- a/src/data_forms.py
+++ b/src/data_forms.py
@@ -37,6 +37,7 @@ class DataFormsTab(Tab):
         self._on_cancel = on_cancel
         self._on_send = on_send
         self._kwargs = kwargs
+        self.fields = []
         for field in self._form:
             self.fields.append(field)
         self.topic_win = windows.Topic()
diff --git a/src/tabs.py b/src/tabs.py
index be56bf01..ecac89b9 100644
--- a/src/tabs.py
+++ b/src/tabs.py
@@ -25,12 +25,11 @@ Windows are displayed, resized, etc
 MIN_WIDTH = 50
 MIN_HEIGHT = 16
 
-from gettext import (bindtextdomain, textdomain, bind_textdomain_codeset,
-                     gettext as _)
-
 import logging
 log = logging.getLogger(__name__)
 
+from gettext import gettext as _)
+
 import windows
 import theme
 import curses
@@ -41,13 +40,14 @@ import common
 import core
 import singleton
 
+import multiuserchat as muc
+
 from sleekxmpp.xmlstream.stanzabase import JID
 from config import config
 from roster import RosterGroup, roster
 from contact import Contact, Resource
 from user import User
 from logger import logger
-import multiuserchat as muc
 
 SHOW_NAME = {
     'dnd': _('busy'),