[formatting] reformat using "black -t py34"

getting rid of thinking about consistent formatting...

core/event.py

@@ -1,6 +1,6 @@
-
 __callbacks = {}
 
+
 def register(event, callback, *args, **kwargs):
     cb = callback
     if len(args) + len(kwargs) > 0:
@@ -8,12 +8,15 @@ def register(event, callback, *args, **kwargs):
 
     __callbacks.setdefault(event, []).append(cb)
 
+
 def clear():
     __callbacks.clear()
 
+
 def trigger(event, *args, **kwargs):
     cb = __callbacks.get(event, [])
-    if len(cb) == 0: return False
+    if len(cb) == 0:
+        return False
 
     for callback in cb:
         if len(args) + len(kwargs) == 0:
@@ -22,4 +25,5 @@ def trigger(event, *args, **kwargs):
             callback(*args, **kwargs)
     return True
 
+
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4