style cleanup: prefer ' for strings

Tomeu prefers ' for strings, so let's use it wherever we don't have a good
reason to use ".

Reviewed-by: James Cameron <quozl@laptop.org>
Acked-by: Simon Schampijer <simon@laptop.org>
CC: Aleksey Lim <alsroot@member.fsf.org>

27 files changed, 134 insertions, 134 deletions

diff --git a/src/sugar/activity/activity.py b/src/sugar/activity/activity.py
index 38d01ba..f222f8c 100644
--- a/src/sugar/activity/activity.py
+++ b/src/sugar/activity/activity.py
@@ -88,9 +88,9 @@ from sugar.activity.widgets import ActivityToolbox
 
 _ = lambda msg: gettext.dgettext('sugar-toolkit', msg)
 
-SCOPE_PRIVATE = "private"
-SCOPE_INVITE_ONLY = "invite"  # shouldn't be shown in UI, it's implicit
-SCOPE_NEIGHBORHOOD = "public"
+SCOPE_PRIVATE = 'private'
+SCOPE_INVITE_ONLY = 'invite'  # shouldn't be shown in UI, it's implicit
+SCOPE_NEIGHBORHOOD = 'public'
 
 J_DBUS_SERVICE = 'org.laptop.Journal'
 J_DBUS_PATH = '/org/laptop/Journal'
@@ -269,7 +269,7 @@ class Activity(Window, gtk.Container):
         # but they get truncated anyway so if more characters
         # are supported in the future we will get a better view
         # of the processes
-        proc_title = "%s <%s>" % (get_bundle_name(), handle.activity_id)
+        proc_title = '%s <%s>' % (get_bundle_name(), handle.activity_id)
         util.set_proc_title(proc_title)
 
         self.connect('realize', self.__realize_cb)
@@ -362,16 +362,16 @@ class Activity(Window, gtk.Container):
 
     def _set_up_sharing(self, mesh_instance, share_scope):
         # handle activity share/join
-        logging.debug("*** Act %s, mesh instance %r, scope %s",
+        logging.debug('*** Act %s, mesh instance %r, scope %s',
                       self._activity_id, mesh_instance, share_scope)
         if mesh_instance is not None:
             # There's already an instance on the mesh, join it
-            logging.debug("*** Act %s joining existing mesh instance %r",
+            logging.debug('*** Act %s joining existing mesh instance %r',
                           self._activity_id, mesh_instance)
             self.shared_activity = mesh_instance
             self.shared_activity.connect('notify::private',
                                          self.__privacy_changed_cb)
-            self._join_id = self.shared_activity.connect("joined",
+            self._join_id = self.shared_activity.connect('joined',
                                                          self.__joined_cb)
             if not self.shared_activity.props.joined:
                 self.shared_activity.join()
@@ -778,7 +778,7 @@ class Activity(Window, gtk.Container):
         its 'private' property.
         """
         if self.shared_activity and self.shared_activity.props.joined:
-            raise RuntimeError("Activity %s already shared." %
+            raise RuntimeError('Activity %s already shared.' %
                                self._activity_id)
         verb = private and 'private' or 'public'
         logging.debug('Requesting %s share of activity %s.', verb,
@@ -880,7 +880,7 @@ class Activity(Window, gtk.Container):
         """Returns the jobject metadata or None if there is no jobject.
 
         Activities can set metadata in write_file() using:
-            self.metadata['MyKey'] = "Something"
+            self.metadata['MyKey'] = 'Something'
 
         and retrieve metadata in read_file() using:
             self.metadata.get('MyKey', 'aDefaultValue')
@@ -976,7 +976,7 @@ def get_activity_root():
     if os.environ.get('SUGAR_ACTIVITY_ROOT'):
         return os.environ['SUGAR_ACTIVITY_ROOT']
     else:
-        raise RuntimeError("No SUGAR_ACTIVITY_ROOT set.")
+        raise RuntimeError('No SUGAR_ACTIVITY_ROOT set.')
 
 
 def show_object_in_journal(object_id):
diff --git a/src/sugar/activity/activityfactory.py b/src/sugar/activity/activityfactory.py
index 46dc346..6bd661f 100644
--- a/src/sugar/activity/activityfactory.py
+++ b/src/sugar/activity/activityfactory.py
@@ -40,16 +40,16 @@ import tempfile
 import subprocess
 import pwd
 
-_SHELL_SERVICE = "org.laptop.Shell"
-_SHELL_PATH = "/org/laptop/Shell"
-_SHELL_IFACE = "org.laptop.Shell"
+_SHELL_SERVICE = 'org.laptop.Shell'
+_SHELL_PATH = '/org/laptop/Shell'
+_SHELL_IFACE = 'org.laptop.Shell'
 
-_ACTIVITY_FACTORY_INTERFACE = "org.laptop.ActivityFactory"
+_ACTIVITY_FACTORY_INTERFACE = 'org.laptop.ActivityFactory'
 
 # helper method to close all filedescriptors
 # borrowed from subprocess.py
 try:
-    MAXFD = os.sysconf("SC_OPEN_MAX")
+    MAXFD = os.sysconf('SC_OPEN_MAX')
 except ValueError:
     MAXFD = 256
 
@@ -284,7 +284,7 @@ class ActivityCreationHandler(gobject.GObject):
             self._handle.activity_id, self._service_name)
 
     def _create_error_handler(self, err):
-        logging.error("Couldn't create activity %s (%s): %s",
+        logging.error('Couldn't create activity %s (%s): %s',
             self._handle.activity_id, self._service_name, err)
         self._shell.NotifyLaunchFailure(
             self._handle.activity_id, reply_handler=self._no_reply_handler,
@@ -293,7 +293,7 @@ class ActivityCreationHandler(gobject.GObject):
     def _find_object_reply_handler(self, jobjects, count):
         if count > 0:
             if count > 1:
-                logging.debug("Multiple objects has the same activity_id.")
+                logging.debug('Multiple objects has the same activity_id.')
             self._handle.object_id = jobjects[0]['uid']
         self._launch_activity()
 
diff --git a/src/sugar/activity/activityservice.py b/src/sugar/activity/activityservice.py
index ff15471..3fafe8a 100644
--- a/src/sugar/activity/activityservice.py
+++ b/src/sugar/activity/activityservice.py
@@ -25,9 +25,9 @@ import dbus
 import dbus.service
 
 
-_ACTIVITY_SERVICE_NAME = "org.laptop.Activity"
-_ACTIVITY_SERVICE_PATH = "/org/laptop/Activity"
-_ACTIVITY_INTERFACE = "org.laptop.Activity"
+_ACTIVITY_SERVICE_NAME = 'org.laptop.Activity'
+_ACTIVITY_SERVICE_PATH = '/org/laptop/Activity'
+_ACTIVITY_INTERFACE = 'org.laptop.Activity'
 
 
 class ActivityService(dbus.service.Object):
diff --git a/src/sugar/activity/bundlebuilder.py b/src/sugar/activity/bundlebuilder.py
index b4ffff9..084b569 100644
--- a/src/sugar/activity/bundlebuilder.py
+++ b/src/sugar/activity/bundlebuilder.py
@@ -108,7 +108,7 @@ class Builder(object):
         po_dir = os.path.join(self.config.source_dir, 'po')
 
         if not self.config.bundle.is_dir(po_dir):
-            logging.warn("Missing po/ dir, cannot build_locale")
+            logging.warn('Missing po/ dir, cannot build_locale')
             return
 
         locale_dir = os.path.join(self.config.source_dir, 'locale')
@@ -128,8 +128,8 @@ class Builder(object):
             if not os.path.isdir(mo_path):
                 os.makedirs(mo_path)
 
-            mo_file = os.path.join(mo_path, "%s.mo" % self.config.bundle_id)
-            args = ["msgfmt", "--output-file=%s" % mo_file, file_name]
+            mo_file = os.path.join(mo_path, '%s.mo' % self.config.bundle_id)
+            args = ['msgfmt', '--output-file=%s' % mo_file, file_name]
             retcode = subprocess.call(args)
             if retcode:
                 print 'ERROR - msgfmt failed with return code %i.' % retcode
@@ -170,9 +170,9 @@ class Builder(object):
         for path in self.check_manifest():
             manifest.append(path)
 
-        f = open(os.path.join(self.config.source_dir, "MANIFEST"), "wb")
+        f = open(os.path.join(self.config.source_dir, 'MANIFEST'), 'wb')
         for line in manifest:
-            f.write(line + "\n")
+            f.write(line + '\n')
 
 
 class Packager(object):
@@ -399,7 +399,7 @@ def print_commands():
 
     for name, func in globals().items():
         if name.startswith('cmd_'):
-            print "%-20s %s" % (name.replace('cmd_', ''), func.__doc__)
+            print '%-20s %s' % (name.replace('cmd_', ''), func.__doc__)
 
     print '\n(Type "./setup.py <command> --help" for help about a ' \
           'particular command\'s options.'
@@ -407,7 +407,7 @@ def print_commands():
 
 def start(bundle_name=None):
     if bundle_name:
-        logging.warn("bundle_name deprecated, now comes from activity.info")
+        logging.warn('bundle_name deprecated, now comes from activity.info')
 
     parser = OptionParser(usage='[action] [options]')
     parser.disable_interspersed_args()
diff --git a/src/sugar/activity/i18n.py b/src/sugar/activity/i18n.py
index 1c3c893..7b09fc2 100644
--- a/src/sugar/activity/i18n.py
+++ b/src/sugar/activity/i18n.py
@@ -118,7 +118,7 @@ def get_locale_path(bundle_id):
         candidate_dirs[os.environ['SUGAR_LOCALEDIR']] = 2
 
     gconf_client = gconf.client_get_default()
-    package_dir = gconf_client.get_string("/desktop/sugar/i18n/langpackdir")
+    package_dir = gconf_client.get_string('/desktop/sugar/i18n/langpackdir')
     if package_dir is not None and package_dir is not '':
         candidate_dirs[package_dir] = 1
 
diff --git a/src/sugar/activity/main.py b/src/sugar/activity/main.py
index c04257a..d2a9302 100644
--- a/src/sugar/activity/main.py
+++ b/src/sugar/activity/main.py
@@ -56,7 +56,7 @@ class SingleProcess(dbus.service.Object):
         object_path = get_single_process_path(name_service)
         dbus.service.Object.__init__(self, bus_name, object_path)
 
-    @dbus.service.method("org.laptop.SingleProcess", in_signature="a{sv}")
+    @dbus.service.method('org.laptop.SingleProcess', in_signature='a{sv}')
     def create(self, handle_dict):
         handle = activityhandle.create_from_dict(handle_dict)
         create_activity_instance(self.constructor, handle)
@@ -64,14 +64,14 @@ class SingleProcess(dbus.service.Object):
 
 def main():
     parser = OptionParser()
-    parser.add_option("-b", "--bundle-id", dest="bundle_id",
-                      help="identifier of the activity bundle")
-    parser.add_option("-a", "--activity-id", dest="activity_id",
-                      help="identifier of the activity instance")
-    parser.add_option("-o", "--object-id", dest="object_id",
-                      help="identifier of the associated datastore object")
-    parser.add_option("-u", "--uri", dest="uri",
-                      help="URI to load")
+    parser.add_option('-b', '--bundle-id', dest='bundle_id',
+                      help='identifier of the activity bundle')
+    parser.add_option('-a', '--activity-id', dest='activity_id',
+                      help='identifier of the activity instance')
+    parser.add_option('-o', '--object-id', dest='object_id',
+                      help='identifier of the associated datastore object')
+    parser.add_option('-u', '--uri', dest='uri',
+                      help='URI to load')
     parser.add_option('-s', '--single-process', dest='single_process',
                       action='store_true',
                       help='start all the instances in the same process')
diff --git a/src/sugar/bundle/activitybundle.py b/src/sugar/bundle/activitybundle.py
index b21f25d..94c44b0 100644
--- a/src/sugar/bundle/activitybundle.py
+++ b/src/sugar/bundle/activitybundle.py
@@ -87,9 +87,9 @@ class ActivityBundle(Bundle):
         "activity startup.")
 
     def _raw_manifest(self):
-        f = self.get_file("MANIFEST")
+        f = self.get_file('MANIFEST')
         if not f:
-            logging.warning("Activity directory lacks a MANIFEST file.")
+            logging.warning('Activity directory lacks a MANIFEST file.')
             return []
 
         ret = [line.strip() for line in f.readlines()]
@@ -108,7 +108,7 @@ class ActivityBundle(Bundle):
         lines = self._raw_manifest()
 
         # Remove trailing newlines, they do not help keep absolute position.
-        while lines and lines[-1] == "":
+        while lines and lines[-1] == '':
             lines = lines[:-1]
 
         for num, line in enumerate(lines):
@@ -117,20 +117,20 @@ class ActivityBundle(Bundle):
 
             # Remove duplicates
             if line in lines[0:num]:
-                lines[num] = ""
+                lines[num] = ''
                 logging.warning('Bundle %s: duplicate entry in MANIFEST: %s',
                     self._name, line)
                 continue
 
             # Remove MANIFEST
-            if line == "MANIFEST":
-                lines[num] = ""
+            if line == 'MANIFEST':
+                lines[num] = ''
                 logging.warning('Bundle %s: MANIFEST includes itself: %s',
                     self._name, line)
 
             # Remove invalid files
             if not self.is_file(line):
-                lines[num] = ""
+                lines[num] = ''
                 logging.warning('Bundle %s: invalid entry in MANIFEST: %s',
                     self._name, line)
 
@@ -328,7 +328,7 @@ class ActivityBundle(Bundle):
         for path in paths:
             if path in manifestfiles:
                 manifestfiles.remove(path)
-            elif path != "MANIFEST":
+            elif path != 'MANIFEST':
                 logging.warning('Bundle %s: %s not in MANIFEST', self._name,
                     path)
                 if strict_manifest:
@@ -336,7 +336,7 @@ class ActivityBundle(Bundle):
 
         # Is anything in MANIFEST left over after accounting for all files?
         if manifestfiles:
-            err = ("Bundle %s: files in MANIFEST not included: %s" %
+            err = ('Bundle %s: files in MANIFEST not included: %s' %
                    (self._name, str(manifestfiles)))
             if strict_manifest:
                 raise MalformedBundleException(err)
diff --git a/src/sugar/bundle/bundle.py b/src/sugar/bundle/bundle.py
index cb110cc..8200d49 100644
--- a/src/sugar/bundle/bundle.py
+++ b/src/sugar/bundle/bundle.py
@@ -103,7 +103,7 @@ class Bundle(object):
             if ext != self._unzipped_extension:
                 raise MalformedBundleException(
                     'All files in the bundle must be inside a single ' +
-                    'directory whose name ends with "%s"' %
+                    'directory whose name ends with %r' %
                     self._unzipped_extension)
 
         for file_name in file_names:
@@ -118,7 +118,7 @@ class Bundle(object):
         if self._zip_file is None:
             path = os.path.join(self._path, filename)
             try:
-                f = open(path, "rb")
+                f = open(path, 'rb')
             except IOError:
                 return None
         else:
diff --git a/src/sugar/bundle/contentbundle.py b/src/sugar/bundle/contentbundle.py
index 48e05a1..5411a0f 100644
--- a/src/sugar/bundle/contentbundle.py
+++ b/src/sugar/bundle/contentbundle.py
@@ -97,7 +97,7 @@ class ContentBundle(Bundle):
                 self._l10n = False
             else:
                 raise MalformedBundleException(
-                    'Content bundle %s has invalid l10n key "%s"' %
+                    'Content bundle %s has invalid l10n key %r' %
                     (self._path, l10n))
         else:
             raise MalformedBundleException(
@@ -196,7 +196,7 @@ class ContentBundle(Bundle):
         return os.path.join(self.get_root_dir(), self._activity_start)
 
     def get_start_uri(self):
-        return "file://" + urllib.pathname2url(self.get_start_path())
+        return 'file://' + urllib.pathname2url(self.get_start_path())
 
     def get_bundle_id(self):
         # TODO treat ContentBundle in special way
diff --git a/src/sugar/datastore/datastore.py b/src/sugar/datastore/datastore.py
index 2b01366..ed05634 100644
--- a/src/sugar/datastore/datastore.py
+++ b/src/sugar/datastore/datastore.py
@@ -35,9 +35,9 @@ from sugar import env
 from sugar import mime
 from sugar import dispatch
 
-DS_DBUS_SERVICE = "org.laptop.sugar.DataStore"
-DS_DBUS_INTERFACE = "org.laptop.sugar.DataStore"
-DS_DBUS_PATH = "/org/laptop/sugar/DataStore"
+DS_DBUS_SERVICE = 'org.laptop.sugar.DataStore'
+DS_DBUS_INTERFACE = 'org.laptop.sugar.DataStore'
+DS_DBUS_PATH = '/org/laptop/sugar/DataStore'
 
 _data_store = None
 
@@ -316,8 +316,8 @@ def create():
 def _update_ds_entry(uid, properties, filename, transfer_ownership=False,
         reply_handler=None, error_handler=None, timeout=-1):
     debug_properties = properties.copy()
-    if "preview" in debug_properties:
-        debug_properties["preview"] = "<omitted>"
+    if 'preview' in debug_properties:
+        debug_properties['preview'] = '<omitted>'
     logging.debug('dbus_helpers.update: %s, %s, %s, %s', uid, filename,
         debug_properties, transfer_ownership)
     if reply_handler and error_handler:
diff --git a/src/sugar/env.py b/src/sugar/env.py
index a427d65..1ef8f34 100644
--- a/src/sugar/env.py
+++ b/src/sugar/env.py
@@ -34,7 +34,7 @@ def get_profile_path(path=None):
         try:
             os.makedirs(base, 0770)
         except OSError:
-            print "Could not create user directory."
+            print 'Could not create user directory.'
 
     if path != None:
         return os.path.join(base, path)
diff --git a/src/sugar/graphics/alert.py b/src/sugar/graphics/alert.py
index f032871..5298430 100644
--- a/src/sugar/graphics/alert.py
+++ b/src/sugar/graphics/alert.py
@@ -145,7 +145,7 @@ class Alert(gtk.EventBox):
         if pspec.name == 'title':
             if self._title != value:
                 self._title = value
-                self._title_label.set_markup("<b>" + self._title + "</b>")
+                self._title_label.set_markup('<b>' + self._title + '</b>')
         elif pspec.name == 'msg':
             if self._msg != value:
                 self._msg = value
diff --git a/src/sugar/graphics/combobox.py b/src/sugar/graphics/combobox.py
index bc759c2..09554e5 100644
--- a/src/sugar/graphics/combobox.py
+++ b/src/sugar/graphics/combobox.py
@@ -65,7 +65,7 @@ class ComboBox(gtk.ComboBox):
         width, height = gtk.icon_size_lookup(size)
         info = icon_theme.lookup_icon(name, max(width, height), 0)
         if not info:
-            raise ValueError("Icon '" + name + "' not found.")
+            raise ValueError('Icon %r not found.' % name)
         fname = info.get_filename()
         del info
         return fname
diff --git a/src/sugar/graphics/icon.py b/src/sugar/graphics/icon.py
index ea3a9c0..870c49e 100644
--- a/src/sugar/graphics/icon.py
+++ b/src/sugar/graphics/icon.py
@@ -247,7 +247,7 @@ class _IconBuffer(object):
         #   -- 2007-12-14 Benjamin Berg
         pixbuf = widget.style.render_icon(icon_source, widget.get_direction(),
                                           gtk.STATE_INSENSITIVE, -1, widget,
-                                          "sugar-icon")
+                                          'sugar-icon')
 
         return pixbuf
 
diff --git a/src/sugar/graphics/objectchooser.py b/src/sugar/graphics/objectchooser.py
index 590e35d..af9142d 100644
--- a/src/sugar/graphics/objectchooser.py
+++ b/src/sugar/graphics/objectchooser.py
@@ -68,8 +68,8 @@ class ObjectChooser(object):
         self._bus = dbus.SessionBus(mainloop=self._main_loop)
         self._bus.add_signal_receiver(
                 self.__name_owner_changed_cb,
-                signal_name="NameOwnerChanged",
-                dbus_interface="org.freedesktop.DBus",
+                signal_name='NameOwnerChanged',
+                dbus_interface='org.freedesktop.DBus',
                 arg0=J_DBUS_SERVICE)
 
         obj = self._bus.get_object(J_DBUS_SERVICE, J_DBUS_PATH)
diff --git a/src/sugar/graphics/palettewindow.py b/src/sugar/graphics/palettewindow.py
index 0250f4a..38331ad 100644
--- a/src/sugar/graphics/palettewindow.py
+++ b/src/sugar/graphics/palettewindow.py
@@ -165,7 +165,7 @@ class PaletteWindow(gtk.Window):
         self.set_data('sugar-accel-group', accel_group)
         self.add_accel_group(accel_group)
 
-        self.set_group_id("default")
+        self.set_group_id('default')
 
         self.connect('show', self.__show_cb)
         self.connect('hide', self.__hide_cb)
@@ -279,12 +279,12 @@ class PaletteWindow(gtk.Window):
 
         if gap:
             wstyle.paint_box_gap(event.window, gtk.STATE_PRELIGHT,
-                                 gtk.SHADOW_IN, event.area, self, "palette",
+                                 gtk.SHADOW_IN, event.area, self, 'palette',
                                  0, 0, allocation.width, allocation.height,
                                  gap[0], gap[1], gap[2])
         else:
             wstyle.paint_box(event.window, gtk.STATE_PRELIGHT,
-                             gtk.SHADOW_IN, event.area, self, "palette",
+                             gtk.SHADOW_IN, event.area, self, 'palette',
                              0, 0, allocation.width, allocation.height)
 
         # Fall trough to the container expose handler.
@@ -740,14 +740,14 @@ class WidgetInvoker(Invoker):
         if gap:
             wstyle.paint_box_gap(event.window, gtk.STATE_PRELIGHT,
                                  gtk.SHADOW_IN, event.area, self._widget,
-                                 "palette-invoker", x, y,
+                                 'palette-invoker', x, y,
                                  self._widget.allocation.width,
                                  self._widget.allocation.height,
                                  gap[0], gap[1], gap[2])
         else:
             wstyle.paint_box(event.window, gtk.STATE_PRELIGHT,
                              gtk.SHADOW_IN, event.area, self._widget,
-                             "palette-invoker", x, y,
+                             'palette-invoker', x, y,
                              self._widget.allocation.width,
                              self._widget.allocation.height)
 
diff --git a/src/sugar/graphics/radiotoolbutton.py b/src/sugar/graphics/radiotoolbutton.py
index 37267b4..b5fabf2 100644
--- a/src/sugar/graphics/radiotoolbutton.py
+++ b/src/sugar/graphics/radiotoolbutton.py
@@ -175,7 +175,7 @@ class RadioToolButton(gtk.RadioToolButton):
         elif child.state == gtk.STATE_PRELIGHT:
             child.style.paint_box(event.window, gtk.STATE_PRELIGHT,
                                   gtk.SHADOW_NONE, event.area,
-                                  child, "toolbutton-prelight",
+                                  child, 'toolbutton-prelight',
                                   allocation.x, allocation.y,
                                   allocation.width, allocation.height)
 
diff --git a/src/sugar/graphics/toggletoolbutton.py b/src/sugar/graphics/toggletoolbutton.py
index cdaf2f0..012c2b0 100644
--- a/src/sugar/graphics/toggletoolbutton.py
+++ b/src/sugar/graphics/toggletoolbutton.py
@@ -28,7 +28,7 @@ from sugar.graphics.palette import Palette, ToolInvoker
 
 class ToggleToolButton(gtk.ToggleToolButton):
 
-    __gtype_name__ = "SugarToggleToolButton"
+    __gtype_name__ = 'SugarToggleToolButton'
 
     def __init__(self, named_icon=None):
         gtk.ToggleToolButton.__init__(self)
@@ -82,7 +82,7 @@ class ToggleToolButton(gtk.ToggleToolButton):
         elif child.state == gtk.STATE_PRELIGHT:
             child.style.paint_box(event.window, gtk.STATE_PRELIGHT,
                                   gtk.SHADOW_NONE, event.area,
-                                  child, "toolbutton-prelight",
+                                  child, 'toolbutton-prelight',
                                   allocation.x, allocation.y,
                                   allocation.width, allocation.height)
 
diff --git a/src/sugar/graphics/toolbutton.py b/src/sugar/graphics/toolbutton.py
index f15e406..25833b6 100644
--- a/src/sugar/graphics/toolbutton.py
+++ b/src/sugar/graphics/toolbutton.py
@@ -59,7 +59,7 @@ def setup_accelerator(tool_button):
 
 class ToolButton(gtk.ToolButton):
 
-    __gtype_name__ = "SugarToolButton"
+    __gtype_name__ = 'SugarToolButton'
 
     def __init__(self, icon_name=None, **kwargs):
         self._accelerator = None
@@ -151,7 +151,7 @@ class ToolButton(gtk.ToolButton):
         elif child.state == gtk.STATE_PRELIGHT:
             child.style.paint_box(event.window, gtk.STATE_PRELIGHT,
                                   gtk.SHADOW_NONE, event.area,
-                                  child, "toolbutton-prelight",
+                                  child, 'toolbutton-prelight',
                                   allocation.x, allocation.y,
                                   allocation.width, allocation.height)
 
diff --git a/src/sugar/graphics/tray.py b/src/sugar/graphics/tray.py
index 0e048d8..fb98d89 100644
--- a/src/sugar/graphics/tray.py
+++ b/src/sugar/graphics/tray.py
@@ -396,7 +396,7 @@ class TrayButton(ToolButton):
 
 class _IconWidget(gtk.EventBox):
 
-    __gtype_name__ = "SugarTrayIconWidget"
+    __gtype_name__ = 'SugarTrayIconWidget'
 
     def __init__(self, icon_name=None, xo_color=None):
         gtk.EventBox.__init__(self)
@@ -422,7 +422,7 @@ class _IconWidget(gtk.EventBox):
 
 class TrayIcon(gtk.ToolItem):
 
-    __gtype_name__ = "SugarTrayIcon"
+    __gtype_name__ = 'SugarTrayIcon'
 
     def __init__(self, icon_name=None, xo_color=None):
         gtk.ToolItem.__init__(self)
diff --git a/src/sugar/graphics/xocolor.py b/src/sugar/graphics/xocolor.py
index fd329cb..df60917 100644
--- a/src/sugar/graphics/xocolor.py
+++ b/src/sugar/graphics/xocolor.py
@@ -261,7 +261,7 @@ class XoColor:
         return '%s,%s' % (self.stroke, self.fill)
 
 
-if __name__ == "__main__":
+if __name__ == '__main__':
     import sys
     import re
 
diff --git a/src/sugar/network.py b/src/sugar/network.py
index 069a980..34d496c 100644
--- a/src/sugar/network.py
+++ b/src/sugar/network.py
@@ -147,12 +147,12 @@ class ChunkedGlibHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
         """
         path = self.translate_path(self.path)
         if not path or not os.path.exists(path):
-            self.send_error(404, "File not found")
+            self.send_error(404, 'File not found')
             return None
 
         f = None
         if os.path.isdir(path):
-            for index in "index.html", "index.htm":
+            for index in 'index.html', 'index.htm':
                 index = os.path.join(path, index)
                 if os.path.exists(index):
                     path = index
@@ -166,12 +166,12 @@ class ChunkedGlibHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
             # transmitted *less* than the content-length!
             f = open(path, 'rb')
         except IOError:
-            self.send_error(404, "File not found")
+            self.send_error(404, 'File not found')
             return None
         self.send_response(200)
-        self.send_header("Content-type", ctype)
-        self.send_header("Content-Length", str(os.fstat(f.fileno())[6]))
-        self.send_header("Content-Disposition", 'attachment; filename="%s"' %
+        self.send_header('Content-type', ctype)
+        self.send_header('Content-Length', str(os.fstat(f.fileno())[6]))
+        self.send_header('Content-Disposition', 'attachment; filename="%s"' %
                          os.path.basename(path))
         self.end_headers()
         return f
@@ -209,8 +209,8 @@ class GlibURLDownloader(gobject.GObject):
         self._outf = None
         self._fname = None
         if destfd and not destfile:
-            raise ValueError("Must provide destination file too when" \
-                             "specifying file descriptor")
+            raise ValueError('Must provide destination file too when'
+                             ' specifying file descriptor')
         if destfile:
             self._suggested_fname = os.path.basename(destfile)
             self._fname = os.path.abspath(os.path.expanduser(destfile))
@@ -238,15 +238,15 @@ class GlibURLDownloader(gobject.GObject):
 
     def cancel(self):
         if self._srcid == 0:
-            raise RuntimeError("Download already canceled or stopped")
+            raise RuntimeError('Download already canceled or stopped')
         self.cleanup(remove=True)
 
     def _get_filename_from_headers(self, headers):
         if 'Content-Disposition' not in headers:
             return None
 
-        ftag = "filename="
-        data = headers["Content-Disposition"]
+        ftag = 'filename='
+        data = headers['Content-Disposition']
         fidx = data.find(ftag)
         if fidx < 0:
             return None
@@ -260,7 +260,7 @@ class GlibURLDownloader(gobject.GObject):
     def _read_next_chunk(self, source, condition):
         if condition & gobject.IO_ERR:
             self.cleanup(remove=True)
-            self.emit("error", "Error downloading file.")
+            self.emit('error', 'Error downloading file.')
             return False
         elif not (condition & gobject.IO_IN):
             # shouldn't get here, but...
@@ -274,19 +274,19 @@ class GlibURLDownloader(gobject.GObject):
             # error writing data to file?
             if count < len(data):
                 self.cleanup(remove=True)
-                self.emit("error", "Error writing to download file.")
+                self.emit('error', 'Error writing to download file.')
                 return False
 
-            self.emit("progress", self._written)
+            self.emit('progress', self._written)
 
             # done?
             if len(data) < self.CHUNK_SIZE:
                 self.cleanup()
-                self.emit("finished", self._fname, self._suggested_fname)
+                self.emit('finished', self._fname, self._suggested_fname)
                 return False
         except Exception, err:
             self.cleanup(remove=True)
-            self.emit("error", "Error downloading file: %s" % err)
+            self.emit('error', 'Error downloading file: %r' % err)
             return False
         return True
 
diff --git a/src/sugar/presence/activity.py b/src/sugar/presence/activity.py
index f169e18..8057841 100644
--- a/src/sugar/presence/activity.py
+++ b/src/sugar/presence/activity.py
@@ -180,7 +180,7 @@ class Activity(gobject.GObject):
     def do_get_property(self, pspec):
         """Retrieve a particular property from our property dictionary"""
 
-        if pspec.name == "joined":
+        if pspec.name == 'joined':
             return self._joined
 
         if self._get_properties_call is not None:
@@ -188,17 +188,17 @@ class Activity(gobject.GObject):
                           'wants property %s', self, pspec.name)
             self._get_properties_call.block()
 
-        if pspec.name == "id":
+        if pspec.name == 'id':
             return self._id
-        elif pspec.name == "name":
+        elif pspec.name == 'name':
             return self._name
-        elif pspec.name == "color":
+        elif pspec.name == 'color':
             return self._color
-        elif pspec.name == "type":
+        elif pspec.name == 'type':
             return self._type
-        elif pspec.name == "tags":
+        elif pspec.name == 'tags':
             return self._tags
-        elif pspec.name == "private":
+        elif pspec.name == 'private':
             return self._private
 
     def do_set_property(self, pspec, val):
@@ -206,16 +206,16 @@ class Activity(gobject.GObject):
         # FIXME: need an asynchronous API to set these properties,
         # particularly 'private'
 
-        if pspec.name == "name":
+        if pspec.name == 'name':
             self._name = val
-        elif pspec.name == "color":
+        elif pspec.name == 'color':
             self._color = val
-        elif pspec.name == "tags":
+        elif pspec.name == 'tags':
             self._tags = val
-        elif pspec.name == "private":
+        elif pspec.name == 'private':
             self._private = val
         else:
-            raise ValueError('Unknown property "%s"', pspec.name)
+            raise ValueError('Unknown property %r', pspec.name)
 
         self._publish_properties()
 
@@ -457,7 +457,7 @@ class Activity(gobject.GObject):
     # Leaving
     def __text_channel_closed_cb(self):
         self._joined = False
-        self.emit("joined", False, "left activity")
+        self.emit('joined', False, 'left activity')
 
     def leave(self):
         """Leave this shared activity"""
diff --git a/src/sugar/presence/buddy.py b/src/sugar/presence/buddy.py
index 8493ce5..eaba3e3 100644
--- a/src/sugar/presence/buddy.py
+++ b/src/sugar/presence/buddy.py
@@ -244,5 +244,5 @@ class Owner(BaseBuddy):
         BaseBuddy.__init__(self)
 
         client = gconf.client_get_default()
-        self.props.nick = client.get_string("/desktop/sugar/user/nick")
-        self.props.color = client.get_string("/desktop/sugar/user/color")
+        self.props.nick = client.get_string('/desktop/sugar/user/nick')
+        self.props.color = client.get_string('/desktop/sugar/user/color')
diff --git a/src/sugar/presence/presenceservice.py b/src/sugar/presence/presenceservice.py
index e183446..b6c581e 100644
--- a/src/sugar/presence/presenceservice.py
+++ b/src/sugar/presence/presenceservice.py
@@ -82,7 +82,7 @@ class PresenceService(gobject.GObject):
             for account_path, connection in connections_per_account.items():
                 if not connection.connected:
                     continue
-                logging.debug("Calling GetActivity on %s", account_path)
+                logging.debug('Calling GetActivity on %s', account_path)
                 try:
                     room_handle = connection.connection.GetActivity(
                             activity_id,
@@ -172,12 +172,12 @@ class PresenceService(gobject.GObject):
     def __share_activity_cb(self, activity):
         """Finish sharing the activity
         """
-        self.emit("activity-shared", True, activity, None)
+        self.emit('activity-shared', True, activity, None)
 
     def __share_activity_error_cb(self, activity, error):
         """Notify with GObject event of unsuccessful sharing of activity
         """
-        self.emit("activity-shared", False, activity, error)
+        self.emit('activity-shared', False, activity, error)
 
     def share_activity(self, activity, properties=None, private=True):
         if properties is None:
diff --git a/src/sugar/profile.py b/src/sugar/profile.py
index 2ed5aa6..8a76d2c 100644
--- a/src/sugar/profile.py
+++ b/src/sugar/profile.py
@@ -69,8 +69,8 @@ class Profile(object):
 
     def is_valid(self):
         client = gconf.client_get_default()
-        nick = client.get_string("/desktop/sugar/user/nick")
-        color = client.get_string("/desktop/sugar/user/color")
+        nick = client.get_string('/desktop/sugar/user/nick')
+        color = client.get_string('/desktop/sugar/user/color')
 
         return nick is not '' and \
                color is not '' and \
@@ -84,21 +84,21 @@ class Profile(object):
             return None
 
         try:
-            f = open(key_path, "r")
+            f = open(key_path, 'r')
             lines = f.readlines()
             f.close()
         except IOError:
             logging.exception('Error reading public key')
             return None
 
-        magic = "ssh-dss "
+        magic = 'ssh-dss '
         for l in lines:
             l = l.strip()
             if not l.startswith(magic):
                 continue
             return l[len(magic):]
         else:
-            logging.error("Error parsing public key.")
+            logging.error('Error parsing public key.')
             return None
 
     def _hash_private_key(self):
@@ -108,7 +108,7 @@ class Profile(object):
             return None
 
         try:
-            f = open(key_path, "r")
+            f = open(key_path, 'r')
             lines = f.readlines()
             f.close()
         except IOError:
@@ -120,15 +120,15 @@ class Profile(object):
         end_found = False
         for l in lines:
             l = l.strip()
-            if l.startswith("-----BEGIN DSA PRIVATE KEY-----"):
+            if l.startswith('-----BEGIN DSA PRIVATE KEY-----'):
                 begin_found = True
                 continue
-            if l.startswith("-----END DSA PRIVATE KEY-----"):
+            if l.startswith('-----END DSA PRIVATE KEY-----'):
                 end_found = True
                 continue
             key += l
         if not (len(key) and begin_found and end_found):
-            logging.error("Error parsing public key.")
+            logging.error('Error parsing public key.')
             return None
 
         # hash it
@@ -145,41 +145,41 @@ class Profile(object):
         if cp.has_option('Buddy', 'NickName'):
             name = cp.get('Buddy', 'NickName')
             # decode nickname from ascii-safe chars to unicode
-            nick = name.decode("utf-8")
-            client.set_string("/desktop/sugar/user/nick", nick)
+            nick = name.decode('utf-8')
+            client.set_string('/desktop/sugar/user/nick', nick)
         if cp.has_option('Buddy', 'Color'):
             color = cp.get('Buddy', 'Color')
-            client.set_string("/desktop/sugar/user/color", color)
+            client.set_string('/desktop/sugar/user/color', color)
         if cp.has_option('Jabber', 'Server'):
             server = cp.get('Jabber', 'Server')
-            client.set_string("/desktop/sugar/collaboration/jabber_server",
+            client.set_string('/desktop/sugar/collaboration/jabber_server',
                               server)
         if cp.has_option('Date', 'Timezone'):
             timezone = cp.get('Date', 'Timezone')
-            client.set_string("/desktop/sugar/date/timezone", timezone)
+            client.set_string('/desktop/sugar/date/timezone', timezone)
         if cp.has_option('Frame', 'HotCorners'):
             delay = float(cp.get('Frame', 'HotCorners'))
-            client.set_int("/desktop/sugar/frame/corner_delay", int(delay))
+            client.set_int('/desktop/sugar/frame/corner_delay', int(delay))
         if cp.has_option('Frame', 'WarmEdges'):
             delay = float(cp.get('Frame', 'WarmEdges'))
-            client.set_int("/desktop/sugar/frame/edge_delay", int(delay))
+            client.set_int('/desktop/sugar/frame/edge_delay', int(delay))
         if cp.has_option('Server', 'Backup1'):
             backup1 = cp.get('Server', 'Backup1')
-            client.set_string("/desktop/sugar/backup_url", backup1)
+            client.set_string('/desktop/sugar/backup_url', backup1)
         if cp.has_option('Sound', 'Volume'):
             volume = float(cp.get('Sound', 'Volume'))
-            client.set_int("/desktop/sugar/sound/volume", int(volume))
+            client.set_int('/desktop/sugar/sound/volume', int(volume))
         if cp.has_option('Power', 'AutomaticPM'):
             state = cp.get('Power', 'AutomaticPM')
-            if state.lower() == "true":
-                client.set_bool("/desktop/sugar/power/automatic", True)
+            if state.lower() == 'true':
+                client.set_bool('/desktop/sugar/power/automatic', True)
         if cp.has_option('Power', 'ExtremePM'):
             state = cp.get('Power', 'ExtremePM')
-            if state.lower() == "true":
-                client.set_bool("/desktop/sugar/power/extreme", True)
+            if state.lower() == 'true':
+                client.set_bool('/desktop/sugar/power/extreme', True)
         if cp.has_option('Shell', 'FavoritesLayout'):
             layout = cp.get('Shell', 'FavoritesLayout')
-            client.set_string("/desktop/sugar/desktop/favorites_layout",
+            client.set_string('/desktop/sugar/desktop/favorites_layout',
                               layout)
         del cp
         try:
@@ -225,12 +225,12 @@ def get_profile():
 
 def get_nick_name():
     client = gconf.client_get_default()
-    return client.get_string("/desktop/sugar/user/nick")
+    return client.get_string('/desktop/sugar/user/nick')
 
 
 def get_color():
     client = gconf.client_get_default()
-    color = client.get_string("/desktop/sugar/user/color")
+    color = client.get_string('/desktop/sugar/user/color')
     return XoColor(color)
 
 
diff --git a/src/sugar/util.py b/src/sugar/util.py
index 9604dbf..083a46b 100644
--- a/src/sugar/util.py
+++ b/src/sugar/util.py
@@ -64,7 +64,7 @@ def unique_id(data=''):
         to be unique-enough, no attempt is made to make
         perfectly unique values.
     """
-    data_string = "%s%s%s" % (time.time(), random.randint(10000, 100000), data)
+    data_string = '%s%s%s' % (time.time(), random.randint(10000, 100000), data)
     return printable_hash(sha_data(data_string))