try:
event.data = (_event_mappings[event_type]).deserialize(event.data)
except KeyError: # else, if custom event, then event.data is dict and should be set to None
event.data = None
try:
event.data = (_event_mappings[event_type]).deserialize(event.data)
except KeyError: # else, if custom event, then event.data is dict and should be set to None
pass
should be