--- a/src/server/utils.py	Sun Jun 24 22:21:25 2018 +0200
+++ b/src/server/utils.py	Fri Jun 29 17:45:26 2018 +0200
@@ -22,16 +22,18 @@
 from sat.core import exceptions
 from sat.core.log import getLogger
 import urllib
+
 log = getLogger(__name__)
 
 
-def quote(value, safe='@'):
+def quote(value, safe="@"):
     """shortcut to quote an unicode value for URL"""
-    return urllib.quote(value.encode('utf-8'), safe=safe)
+    return urllib.quote(value.encode("utf-8"), safe=safe)
 
 
 class ProgressHandler(object):
     """class to help the management of progressions"""
+
     handlers = {}
 
     def __init__(self, host, progress_id, profile):
@@ -44,34 +46,40 @@
         handlers = cls.handlers
         if profile in handlers and progress_id in handlers[profile]:
             handler_data = handlers[profile][progress_id]
-            timeout = handler_data[u'timeout']
+            timeout = handler_data[u"timeout"]
             if timeout.active():
                 timeout.cancel()
             cb = handler_data[name]
             if cb is not None:
                 cb(data)
-            if name == u'started':
+            if name == u"started":
                 pass
-            elif name == u'finished':
-                handler_data[u'deferred'].callback(data)
-                handler_data[u'instance'].unregister_handler()
-            elif name == u'error':
-                handler_data[u'deferred'].errback(Exception(data))
-                handler_data[u'instance'].unregister_handler()
+            elif name == u"finished":
+                handler_data[u"deferred"].callback(data)
+                handler_data[u"instance"].unregister_handler()
+            elif name == u"error":
+                handler_data[u"deferred"].errback(Exception(data))
+                handler_data[u"instance"].unregister_handler()
             else:
-                log.error(u'unexpected signal: {name}'.format(name=name))
+                log.error(u"unexpected signal: {name}".format(name=name))
 
     def _timeout(self):
-        log.warning(_(u"No progress received, cancelling handler: {progress_id} [{profile}]").format(
-            progress_id = self.progress_id, profile = self.profile))
+        log.warning(
+            _(
+                u"No progress received, cancelling handler: {progress_id} [{profile}]"
+            ).format(progress_id=self.progress_id, profile=self.profile)
+        )
 
     def unregister_handler(self):
         """remove a previously registered handler"""
         try:
             del self.handlers[self.profile][self.progress_id]
         except KeyError:
-            log.warning(_(u"Trying to remove unknown handler: {progress_id} [{profile}]").format(
-                progress_id = self.progress_id, profile = self.profile))
+            log.warning(
+                _(u"Trying to remove unknown handler: {progress_id} [{profile}]").format(
+                    progress_id=self.progress_id, profile=self.profile
+                )
+            )
         else:
             if not self.handlers[self.profile]:
                 self.handlers[self.profile]
@@ -87,15 +95,19 @@
             an exception is raised
         @return (D(dict[unicode,unicode])): a deferred called when progression is finished
         """
-        handler_data = self.handlers.setdefault(self.profile, {}).setdefault(self.progress_id, {})
+        handler_data = self.handlers.setdefault(self.profile, {}).setdefault(
+            self.progress_id, {}
+        )
         if handler_data:
-            raise exceptions.ConflictError(u"There is already one handler for this progression")
-        handler_data[u'instance'] = self
-        deferred = handler_data[u'deferred'] = defer.Deferred()
-        handler_data[u'started'] = started_cb
-        handler_data[u'finished'] = finished_cb
-        handler_data[u'error'] = error_cb
-        handler_data[u'timeout'] = reactor.callLater(timeout, self._timeout)
+            raise exceptions.ConflictError(
+                u"There is already one handler for this progression"
+            )
+        handler_data[u"instance"] = self
+        deferred = handler_data[u"deferred"] = defer.Deferred()
+        handler_data[u"started"] = started_cb
+        handler_data[u"finished"] = finished_cb
+        handler_data[u"error"] = error_cb
+        handler_data[u"timeout"] = reactor.callLater(timeout, self._timeout)
         return deferred